Bamboo grows like a childs hairor, if you take things literally, at a massively better pace. This exceptionally productive grass species also offers a pleasant feel when used in fabrics, with good breathability and a light, airy sensation. Bamboo fiber is also naturally mildly antimicrobial, which helps reduce the formation of odors. These Kimberley socks are a comfortable choice for relaxed outdoor activities and general use. The feel against the skin is exceptionally soft. - S = 36 - 38 - M= 39 - 42 - L = 43 - 46 Note! Although SealSkinz is best known for its waterproof products, these socks are not waterproof.