WHAT IS THE SAFE FLIP-TOP SYSTEM OF TRAVEL TUMBLER? 15 January 2020 13:40 Updated Follow Our Sip & Go Lid features a 100% leakproof flip-top system, so you can sip easily and safely while on the go. Related articles IS TRAVEL TUMBLER INSULATED? IS TRAVEL TUMBLER LEAKPROOF? HOW AND WHERE DO YOU MANUFACTURE YOUR PRODUCTS? HOW CAN I CLEAN MY SIP&GO LID? DOES TRAVEL TUMBLER FIT CAR CUP HOLDERS?