The Arc'teryx Women's Beta AR Pants are a highly-rated and popular choice for ski mountaineering. These pants are made from a durable and waterproof GORE-TEX fabric, which provides excellent protection from the elements. The Beta AR Pants feature a slim fit and articulated knees, allowing for a comfortable and ergonomic fit. They also have a range of features designed specifically for ski mountaineering, such as reinforced knees and seat, adjustable waistband, and integrated gaiters. With their high-quality construction and attention to detail, the Arc'teryx Beta AR Pants are a top choice for serious ski mountaineers.