Insulates your hot drinks to keep them hot longer, and your cold drinks cool. At a very light 43 grams this cozy is the perfect insulator to accompany your 32 ounce Nalgene water bottle. Constructed from a composite waterproof reflective material, Primaloft Insulation, and waterproof inner nylon liner, this cozy has an inner and outer insulated layer that can be turned inside out for cleaning and drying. The top is closed with an insulated flap and drawcord.