1. 316 mirror inner tank, not easy to leave bacteria 2. The lid of the cup can be used as a water cup, and the strap can be carried on the back and carried freely 3. The silicone ring is matched with the threaded cup cover, which is leak-proof 4. Liner material: 316 stainless steel 5. Shell material: 304 stainless steel 6. Insulation performance: 12-24 hours