Hydro Flask's 32 Oz Wide Flex Straw Cap belongs to their large collection of First Aid products. This cap features TempShield double-wall vacuum insulation, which keeps drinks cold for up to 24 hours and hot for up to 12 hours. The Insulated Flex Straw Cap is leakproof when closed and made with 18/8 pro-grade stainless steel for durability and a pure taste. The wide mouth opening is ice-cube friendly, and the color stays clean and colorful due to the powder coat finish. This bottle fits most backcountry water filters and is BPA-Free. It is also dishwasher safe. However, the Flex Straw Cap is not intended for use with hot liquids and should not be used on a stove, in a microwave, or freezer.