This Libbey Governor Clinton 12 ounce iced tea glass features the wavy, undulating body design and it's rim has been heat-treated with a special rapid heating and cooling process to give it additional resistance to thermal and mechanical shock. This Libbey Governor Clinton glass also comes with Libbey's Safedge Rim Guarantee, their promise that if the rim on This Libbey Governor Clinton glass ever chips, you can return it to the dealer where you bought it and have it replaced. it is made out of very durable glass which makes it last longer.