Flow non-leaking insulating tumbler This flow tumbler is a double-walled tumbler. On the inside of the tumbler is a foam layer, the outer surface of the tumbler is made of stainless steel. This tumbler can 350ml. The cap is designed to rotate on and off. In the cap is a silicone button from which you can drink. This cap also ensures that it can not leak your drink. At the bottom of the tumbler is an anti-slip layer. The tumbler is available in different colors. You can print your own design or designed your logo on the tumbler. You can print your design or logo in up to 4 colors. Also, you can engrave your logo. The tumbler is free BPA produced.