Leak Proof Tumbler The LeakProof Tumbler is as the name suggests, a non-leaking tumbler. The tumbler is outside stainless steel, inside the tumbler of polypropylene. The tumbler is easy to close with a twist. In the screw cap is a button that you can use to open the lid to drink from it. The LeakProof Tumbler is available in four colors. The tumbler can be printed with your own design or designed your logo. You can print your design or logo in up to 4 colors. You can also engrave your logo. The tumbler was produced BPA Free.