The Groove Insulated Sleeve, from Camel Bak, fits the 0.6L Groove Bottle & is made from Nu Foam which helps keep liquids cool or warm. It also reduces condensation so your other kit doesnt get damp in your pack. Nu Foam provides better insulation than Neoprene. The Groove Insulated Sleeve has a side strap which makes it easy to hold & carry or to strap onto a bag.