Ultralight waterproof, breathable, and windproof pants designed for ski mountaineering and trail running in rainy or snowy conditions. Made with the O2 2.5-layer membrane, waterproof (20,000mm H2O column) and highly breathable (30,000g/m²·24h), they provide maximum protection and comfort for FAST&LIGHT activities. The design features 100% fully taped seams and full-length YKK™ side zippers, allowing quick on-and-off without removing ski mountaineering or trail running boots. They include a dual boot adjustment system, with a zipper and an elastic cord with a tanka, ensuring a perfect and secure fit. Their ergonomic cut supports the natural movement of the knees, providing freedom and comfort with every step. Additionally, they are packable into their own pocket, making them an essential garment for high-intensity competitions and training in adverse weather conditions.
FAST&LIGHT - 161g (XS)
Activity
Skimo, Trail Running
Equipment
Full-length YKK™ Coil® side zippers
Dual zipper pullers for quick and complete removal of the pants
Double adjustment system at the hem (zipper + elastic)
One-hand puller on the rear pocket for easy grip while wearing gloves
Custom Width waist adjustment system with Velcro (elastic + precision cord)
Packable into its own rear pocket
Reflective logos on the front and back, 360° visibility
Top Layer Fit: designed to be worn over other garments
Exceeds the mandatory gear requirements for ultra-trail or ski mountaineering competitions
Technology
The O2 pants are designed for aerobic activities under intense use. We have developed a custom fabric for this garment, following our FAST&LIGHT design philosophy, in collaboration with one of Japan's leading textile manufacturers. This jacket combines high waterproof/breathable capacity and durability in an ultra-light fabric (60 g/m²).
Fabric: O2 2.5-layer fabric designed for maximum lightness and technical performance (100% Nylon Ripstop, 60 g/m²). Hydrophilic polyurethane membrane with an excellent balance between waterproofing and breathability.
Guaranteed 20,000 mm waterproofing (TEST JIS L1092:2009 - 7.1.2), ideal for heavy rain conditions. High breathability of 30,000 g/(m²·24h) (TEST JIS L1099:2006 METHOD B1), ensuring comfort during high-intensity activities. DWR C6 treatment (Durable Water Repellency) 80/20 for durable water repellency and protection against surface moisture.
Weight
Size XS: 161 grams | Size S: 166 grams | Size M: 171 grams | Size L: 176 grams | Size XL: 181 grams
Maintenance
For proper maintenance of O2 - 2.5 layer membranes follow these recommendations:
1. It is important to wash the garment regularly, especially after wearing it in a sweaty, intense aerobic situation or after being exposed to a chemical that may affect its properties.
2. Wash the garment alone or with other breathable waterproof garments. Do not wash inside out.
3. Machine wash (never hand wash) in cold water at 30°C.
4. Do not use softeners.
5. Use liquid detergent, do not use bleach, avoid powdered detergents.
6. To increase the duration of the garment and its properties, we recommend the use of Nikwax® specific products.
7. Rinse several times (at least two rinse cycles) if necessary, until it doesn't have any soap smell.
Size Guide
Suggested Size Reference (Height/Weight) - *Designed to be worn over other garments*
| kg / cm | 155 | 160 | 165 | 170 | 175 | 180 | 185 | 190 |
| 50 |
XS |
XS |
XS |
|
|
|
|
|
| 55 |
XS |
XS |
XS |
S |
|
|
|
|
| 60 |
XS |
XS |
XS |
S |
M |
|
|
|
| 65 |
|
S |
S |
M |
M |
L |
|
|
| 70 |
|
|
S |
M |
M |
L |
L |
|
| 75 |
|
|
|
M |
M |
L |
L |
L |
| 80 |
|
|
|
|
L |
L |
L |
L |
| 85 |
|
|
|
|
|
L |
L |
L |
Garment Measurements (cm.)
| Size | A | B | C | D |
| XS |
44 |
50 |
102 |
76 |
| S |
47 |
52 |
105 |
78 |
| M |
49 |
54 |
108 |
81 |
| L |
51 |
56 |
111 |
83 |
| XL |
53 |
58 |
111 |
83 |