Thermal clothing set Finntrail SUBZERO Black 6404
Code: 6404Black-SPrice 79 €In stock: 0 pcsFree delivery in LT, LV and EE · 24-month warranty · 30-day returns · Wrong size? We will swap it
Not sure about the size? Tell us your height, waist and what you will wear underneath. We will tell you which size is yours.
This size is currently unavailable. Write to us and we will let you know when it arrives.
This size is currently unavailable. Write to us and we will let you know when it arrives.
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Finntrail · Base layer
Finntrail SUBZERO Black 6404 Base Layer Set
A base layer for extreme cold, from –30 °C to 0 °C: the WAFFLE-KNIT structure traps heat against the body. The Finntrail SUBZERO Black 6404 set is for days when cold is the main problem. The waffle knit builds pockets of air, and air is what actually keeps you warm. The high collar with a ¾ zip covers the neck and can be opened when you get too warm, the anatomical cut sits close to the body, and the flat seams do not chafe even under several layers.
Who it is for
Made for deep winter cold, when there is little movement and you get cold fast.
- •Snowmobiling and riding into the wind.
- •Winter expeditions and travel.
- •Ice fishing and long stops in the cold.
When it shines
Best from –30 °C to 0 °C: this is a thicker, warmer base layer. In milder weather or with a lot of movement, the versatile ALL SEASON set is more comfortable.
Technical specs
Materials & technology
WAFFLE-KNIT structure
The waffle knit builds pockets of air between the fabric and the skin. It is that air that holds the heat, so the same thickness warms better than a smooth knit.
High collar with a ¾ zip
The collar covers the neck, where heat is lost fastest, and the zip lets you dump excess heat without undressing.
Anatomical cut
The cut sits close to the body, so the fabric touches the skin and can do its job. A loose base layer holds no heat.
Flat seams
Flat seams do not rub the skin even when there are several layers, a backpack or wader braces on top.
Layering
This is the first of three layers: the base layer against the skin, fleece for warmth and a membrane layer against wind and moisture. Together they work better than one thick garment.
How it differs from a versatile base layer
Care
Wash at 30 °C on a gentle cycle with a detergent made for wool and merino (Mountval Wool Wash). Skip the softener: it coats the fibre and the base layer stops wicking moisture. Odour is handled by a rinse-cycle freshener (Mountval Silver Freshness). Dry flat, away from radiators and direct sun.
Frequently asked questions
What does WAFFLE-KNIT mean?
It is a waffle shaped knit that leaves pockets of air between the yarns. Air is a good insulator, so this fabric warms better than a smooth knit of the same thickness.
How does it differ from the ALL SEASON set?
SUBZERO 6404 is made for –30 °C to 0 °C, it is warmer and has a high collar with a ¾ zip. ALL SEASON is thinner and versatile, from –15 °C to +15 °C.
Can I wear it while moving actively?
You can, but with long, hard movement it may get too warm. That is what the ¾ zip is for: open it and heat escapes, close it again when you stop.
Is a base layer alone enough in the cold?
No, this is the first layer. Above it you need a warming layer such as fleece, and on top a layer that stops wind and moisture, that is a membrane suit or jacket.
How do I wash it?
Wash at 30 °C on a gentle cycle with a wool and merino detergent (Mountval Wool Wash), without softener. Odour is handled by a rinse-cycle freshener (Mountval Silver Freshness), and drying should be flat.
What about warranty and returns?
We give a 24 month warranty, you can return within 30 days, and delivery to Lithuania, Latvia and Estonia is free with a tracking number.
Peace of mind
Warranty
2-year warranty. We resolve manufacturing defects quickly, without bureaucracy.
Returns
Not right? Return within 30 days. We will help you pick another size.
Delivery
Free delivery to Lithuania, Latvia and Estonia with a tracking number.
Not sure about the size? Send us your height and chest measurement, we will pick the right one.
And if you want an answer even faster, ask the Finntrail AI assistant (the ASK button on the page), you will usually get a reply right away.
Register this item in the Finntrail Club
Free annual membrane service, priority repairs, early access to new collections and a care coupon worth 3 % of every purchase at finntrail.lt. Registration is free, no matter where you bought the item.
This chart covers the whole product line. The sizes made for this particular model are shown in the size selector above.
How to Choose the Correct FINNTRAIL Men’s Thermals Size
Choosing the correct FINNTRAIL thermal clothing size ensures comfort, freedom of movement, effective layering and proper protection from weather conditions. A size that is too small may restrict movement and feel tight around the chest or shoulders, while a size that is too large may reduce heat retention and overall fit.
The size chart shows body measurements, not garment measurements. FINNTRAIL gear is designed with extra room for comfort and movement, so sizing should be selected according to your body measurements.
Measure Your Chest Girth
Measure around the fullest part of your chest, keeping the measuring tape horizontal. Stand straight and keep the tape close to the body, but not tight.
How to measure: measure around the widest part of your chest while breathing naturally and keeping your body relaxed.This measurement is especially important when choosing jackets and the upper part of a suit.
Measure Your Waist and Hips
Measure your waist at the narrowest part or where you usually wear your pants. Measure your hips around the widest part.
Important: do not pull in your stomach and do not tighten the measuring tape too much. The gear should leave enough room for movement, base layers and comfortable sitting.If you are choosing a suit or pants, hip and waist measurements are just as important as height.
Measure Inseam and Sleeve Length
Inseam is measured from the crotch to the inside of the ankle. Sleeve length helps determine whether the jacket sleeves will properly cover your arms during active movement.
Recommendation: check these measurements if you are taller, have longer arms or legs, or are choosing between a standard and a longer size.How to Use the Size Chart
Measurement Description Height Body height in centimeters. Chest girth Chest circumference measured around the fullest part of the chest. Waist girth Waist circumference. Hips Hip circumference measured around the widest part of the hips. Inseam Inside leg length from crotch to ankle. Sleeve Sleeve length. First, choose the size according to the main girth measurements — chest, waist and hips. Then check whether the selected size matches your height, inseam and sleeve length.
Reference Size Chart
Size Height Chest Waist Hips Inseam Sleeve XXS 158–162 80–86 70–76 82–88 53–57 53–57 XS 163–167 84–90 74–80 86–92 53–57 55–59 S 168–172 88–98 78–88 90–100 57–61 57–61 SK 168–172 100–110 90–100 102–112 57–61 57–61 M 173–177 96–102 86–92 98–104 57–61 59–63 MK 173–177 108–117 98–106 110–118 59–63 59–63 ML 180–190 96–102 86–92 98–104 63–65 63–65 L 178–182 100–110 90–100 102–112 61–64 61–64 LK 178–182 119–125 106–114 118–128 61–64 61–64 XL 183–187 108–117 98–106 110–118 61–64 63–65 XLK 185–190 124–133 114–122 126–134 63–65 63–65 XXL 185–195 116–125 106–114 118–127 63–65 64–67 XXXL 190–200 124–133 114–122 126–134 65–69 65–69 What Do K and L Size Markings Mean?
S M L XLStandard sizes for men with average body proportions.
MLLonger size for taller users whose girths match size M but who need extra length.
SK MK LK XLKWider sizes for larger chest, waist or hip measurements.
XXL XXXLLarger sizes for taller users or broader body types.
If You Are Between Two Sizes
If your measurements fall between two sizes, choose according to how the gear will be used. Jackets and suits should leave enough room for base layers, while thermals should fit closer to the body without restricting movement.
- If you are choosing a jacket or suit, the larger size is usually the safer choice.
- If you are choosing thermal clothing, the fit should be close but not tight.
- If height matches one size but girths match another, prioritize girth measurements.
- If you will wear additional layers, leave more room.
Important: technical gear should not be too tight. Fabric under tension wears faster and may restrict membrane performance and freedom of movement.Recommendation Before Ordering
Before ordering a FINNTRAIL jacket, suit or thermal clothing, accurately measure your main body parameters. Take measurements while wearing a thin base layer or clothing similar to what you plan to wear under the gear.
Best result: provide your height, chest, waist and hip measurements. If possible, also include inseam and sleeve length.Summary
To choose the correct FINNTRAIL men’s jackets, suits or thermals size, the most important measurements are height, chest girth, waist girth, hips, inseam and sleeve length. A correctly selected size ensures comfort, layering ability, freedom of movement and effective protection for active use.
Product Care Instructions
- Wash membrane clothing only with special detergents, such as Mountval Wash & Care, at a temperature no higher than 30 °C, without fabric softeners or bleach.
- After washing, restore water repellency using Mountval Waterproofing Refresher (wash-in) or a spray-on impregnation, following the product instructions.
- After impregnation, allow the product to dry naturally.
- Repair minor membrane damages with special glue, such as Aquaseal / Aquasure, only on clean and dry surfaces.
- Clean boots by hand, do not use a washing machine; if needed, use impregnation products designed for technical footwear.
Regular care helps maintain water repellency, breathability, and prolongs the product's lifespan.
For more information on how to clean Finntrail clothing and boots after use, see here.
Product delivery
We receive goods at our central warehouse twice per week: on Tuesdays and Fridays.
Depending on the order submission time, goods are included in the corresponding delivery cycle:
Order submission time Goods received Notes Until Tuesday 09:00 Friday Standard schedule. Until Friday 09:00 Next Tuesday Orders placed after 09:00 are moved to the next cycle. Important Due to holidays, inventory checks or other circumstances, delivery may be delayed by 1–3 days.
- Orders are shipped the same day they arrive at the central warehouse.
- Delivery is available to parcel lockers in Lithuania, Latvia and Estonia or by courier to your door.
- Delivery to Lithuania, Latvia and Estonia is free of charge. Courier delivery to other EU countries: Poland €4.99, Germany €9.99, other EU countries €12.99. The final cost is shown at checkout before payment.
Returns
Please inform us about a planned return by email at pagalba@finntrail.lt or by phone +370 614 98366.
- Products can be returned within 30 days from the date of receipt.
- The returned item must be unused, with all tags attached and in the original packaging.
- Returns are free within Lithuania, Latvia and Estonia. From other countries the return shipment is paid by the buyer.
- In Lithuania, Latvia and Estonia, together with the notification about the delivered parcel you will receive a return code allowing you to return the item via any parcel locker.
Available solutions after returning the product:- We will replace it with another size.
- We will suggest the most suitable alternative.
- The refund is issued within 1–2 business days after receiving the returned item.
Membrane waterproofing and breathability
Membrane fabric is usually described using two numbers, often separated by a slash: waterproofness and breathability. The first number indicates waterproofness, the second indicates breathability.
?Waterproofing
This is a sliding scale measured in mm that shows how high a column of water you can suspend over the membrane before it starts to let moisture through.
Waterproof Rating Conditions 0–10,000 mm Light rain, dry snow, light pressure. 11,000–15,000 mm Moderate rain, average snow, light pressure. 16,000–20,000 mm Heavy rain, wet snow, some pressure. 20,000 mm+ Heavy rain, wet snow, high pressure. ?Breathability
This is the amount of moisture by weight that can pass through one square metre of fabric over a period of 24 hours. It is commonly measured in g/m²/24 hrs.
Breathability Rating Level of Breathability 0–5,000 g/m²/24 hrs Low – light exercise. 5,000–15,000 g/m²/24 hrs Medium – medium to high energy activity. 15,000 g/m²/24 hrs+ High – vigorous sustained activity.
