Our Klean Kanteen Wide 40oz water bottle is a favorite for backpackers and outdoor lovers due to it's large size, lightweight single wall construction and wide mouth. The wide mouth fits most backcountry water filters for clean and safe water anywhere. Included Loop Cap has a stainless steel base so your favorite beverage never touches plastic. Compatible with all Klean Kanteen wide mouth caps including our leak proof Café Cap 2.0 when you need a drink through function. Need an insulated water bottle? Buy our Insulated 32oz here.