Built for the long haul. The Endurance Bottle is a 25oz insulated stainless steel water bottle made for trail miles, gym sets, summit pushes, and Tuesday-afternoon hydration alike. This PURE Pristine bottle brings a fully 18-8 stainless steel build, double-wall vacuum insulation with a thermal copper lining, and our patented SiSA™ antimicrobial coating. SiSA™ uses the natural antimicrobial properties of silver — not chemical additives — to eliminate 99% of microbes on the drinkware's surface. The twist-on lid pairs a screw cap with a carry loop — splash-proof, leak-proof, and easy to clip to a pack. Keeps drinks cold for up to 36 hours or hot for 8, BPA-free for guilt-free refills all day.