A stretchable latex strand, great for wrapping nymph bodies. Kiley&';s Nymph Skins are more than just another shell back or wing case material. They are wicked durable and stretchy. There just something about the material that makes it have a super realistic look and feel on a hook. If you are looking for a multi-purpose material for everything from wing cases to bodies this is it. 2yd/pack Kiley&';s Nymph Skins vs Hareline/Wapsi Scud Back - The two materials are similar and share similar uses.Kiley&';s Nymph Skins have more stretch and are thicker. They are made from latex which allows them to be used as a stand alone body material. Scud Back is available in two sizes where as Kiley&';s Nymph Skins are only available in ⅛ inch strips.