Sealskinz Thin Ankle Length Socks An improved design and better fitting sock, which replaces the Ultra Light, this is a thin and lightweight below ankle length waterproof sock. Fine Merino wool lining gives excellent wicking performance. Keeps feet dry and comfortable. Elasticated instep and ankle provides support and ensure a comfortable fit. Suitable for all outdoor activities particularly in warmer weather. Ideal for use with lighter weight walking, running and cycling shoes.