Arc'teryx LEAF Ultra Lightweight Alpha LT Packable pants is great for adverse climates. It's a must for your pack when on any mission. The Alpha LT is waterproof, windproof and highly breathable. It is made from GORE-TEX MN40p-X material that is tough. Works great when doing exertion type activities. Some of the features are: Rubber zip closure, articulated pattern for mobility in the knee and crotch and the hem width accommodates boots. 

Features:

• MN40p-X GORE-TEX 3L fabric is exceptionally durable
• Highly breathable to regulate moisture and temperature during exertion.
• Articulation in the seat and knees provides room for layers to move freely.
• Hip length, two-way WaterTight side zippers are positioned for easy access
• Water-Tight fly zipper; adjustable webbing belt.
• Reinforced instep makes use of a hard wearing fabric and has reduced volume at the hem