Tervis Tumbler Company is an American manufacturer of double-walled, insulated tumblers. The double-wall insulation is created by inserting a liner inside an outer shell, creating a layer of air between them. the 2 liners are then permanently fused together. The insulation reduces condensation and keeps beverages hotter or colder longer than non-insulated cups and glasses
The original technology was developed by two engineers, Frank Cotter and G. Howlett Davis, in Detroit, Michigan in 1946. Their design involves a permanently sealed double-walled tumbler.Cotter and Davis combined the last three letters of their surnames to come back up with the name Tervis. John C.Winslow purchased the Tervis product rights within the 1940s. The Tervis Tumbler Company was incorporated in 1967. All Tervis drinkware continues to be made at the Venice, Florida industrial plant, aside from stainless-steel tumblers, which are made in China