T3 Series is a new thermos that leads it to safe use with the stopper inside applied with the separation prevention technology. The cup designed beautifully in compound curves is a suggestive of a coffee sauce presenting a comfortable atmosphere outside as well. It has bright and warm colors to give the warmth of the thermos in a cold environment. The bottom vulnerable to damage is finished with polypropylene to protect the product against the damage and shock outside. The inside stopper designed in a dual structure for better thermal resistance improved hygiene and safety by applying stainless steel, silicon, and sanitated polypropylene. The T-shaped safety pin at the bottom of the stopper inside prevents the separation of the stopper inside and the burn accident caused by it. The handle in the upper part of the stopper inside is non-slip silicon. All parts of the stopper inside can be completely disassembled and assembled for each cleaning. The matching colors between the exterior of the thermos and the stopper inside raised the degree of completion, and can be disassembled and assembled intuitively by users.