The Beysis Re-usable Coffee Cup is as functional as it is sleek. Made of high quality, double-walled stainless steel it will keep your coffee hot for 12 hours and your ice tea cold for 24. Forget about unreliable spring loaded openings and flip top lids - Beysis designed a silicone sealed, screw top lid so robust you can throw your cup in your bag without the risk of leaks or spills. Beysis spent hours perfecting the ergonomic lip and made the dimensions a perfect fit for most car cup-holders. It's these small details in their proprietary registered design that set our cup apart from the rest. The Beysis Re-usable Coffee Cup. Sturdy. Sustainable. Stunning.