Thermal Rating

HYLJE Thermal Rating is referential. Remember to wear baselayer and midlayer according to current weather conditions. The colder the weather the warmer the underwear. We also suggest that you keep in mind in which kind of conditions you are using the overall to choose right kind of product to your purposes. Choose your overall by estimating how actively you will move wearing it.

Hylje Lammittavyys 2 W250

No flakes: no thermal insulation

One flake: light, maximum 50g/m2 wadding, low thermal insulation

Two flakes: 80g/m2 wadding, medium thermal insulation, well suitable for -15 degrees Celsius

Three flakes: 150g/m2 wadding, high thermal insulation for very cold conditions

Four flakes: thick 200g/m2 wadding, suitable for extremely cold conditions


Breathability rate is announced to functional fabrics which keep the water outside but still let the humidity fade away. There are a few different standards to rate breathability. HYLJE rating can be compared to ASTM E96BW-1995 standard. Grams refer to the amount of humidity which penetrates the laminated fabric in the area of one square meter during 24 hours. The bigger the rate, the more the laminate transfers humidity from inside the gartment to outside of it.

Hylje Hengittavyys 2 W250

No symbol: non-laminated fabric, no breathability rating

One steam symbol: breathability minimum of 4.000 g/m2/ 24 h: product has low breathability and is suitable for very light exercise

Two steam symbols: breathability minimum of 5.000 g/m2/ 24 h: product has medium breathability and is suitable for light & medium exercise

Three steam symbols: breathability minimum of 8.000 g/m2/ 24 h: product has high breathability and is suitable even for active exercise

Four steam symbols: breathability minimum of 8.000 g/m2/ 24 h: product has extremely high breathability and is suitable even for ”real” sports such as long hikes

Water resistance

All HYLJE products marked with drop symbols are water proof. The level of water resistance is indicated with water column. It determines how big pressure of water mass you can suspend over the fabric before it starts to leak. Please notice that the taping of seams and carrying a backbag, for example, also affect to the water resistance of the product.

Hylje Vedenpitavyys 2 W250

No drops: non-laminated fabric, no water resistance

One drop: water proof maximum 5.000 mm: protects against drizzle short time

Two drops: water proof over 8.000 mm: protects well against drizzle and sleet and is suitable for longer stay in wet weather conditions

Three drops: water proof over 10.000 mm: protects against heavier rain for longer period of time and sitting on wet a surface for a shorter time

Four drops: water proof over 12.000 mm: suitable for challenging weather conditions and for heavy rain