The Mushroom Double-Walled Stainless Steel Flask is the perfect bottle for mushroom enthusiasts. Thanks to its secure O-ring seal, this bottle is 100% leakproof and crafted from BPA-free materials. Made from double-wall vacuum-insulated stainless steel, the 500ml Mushroom Flask will keep your drink hot for up to 8 hours, and chilled for 24 hours. This bottle comes equipped with a handy carry handle on the screw-top lid, making it easy to clip to backpacks, belts, or carry by hand.