Water bottles from Klean Kanteen are made of extremely durable 18/8 food-grade stainless steel material. Their double-walled vacuum insulated construction keep the content cold for up to 58 hours. Field rated, environmentally friendly and toxin-free, these sturdy steel construction bottles are highly durable, leakproof, long-lasting and don't retain or impart flavours. TKWide Insulated Bottles can be used as a mug, a thermos or a bottle, and thanks to the wide opening and slim design they are easy to drink from, easily accommodate ice cubes and cleaning brushes, and are fully compatible with most backcountry water filters and standard size cup holders. Insulated water bottles from Klean Kanteen are perfect for hikers, backpackers and travellers, and will keep your drinks fresh, crisp and clean tasting for longer.