Nalgene Backpacker 38 Oz Stainless Bottle 1778-1002 Made from surgical grade 316 (18/10) stainless steel that resists tastes and odors and is easy to clean. Unlike aluminum bottles, these bottles have no lining of any kind. The wide mouth accommodates ice cubes and water filtration devices. The most versatile stainless bottle on the market Compatible with most water fillers with its 63mm opening and standar thread pattern