Model : 15243 DuraTuff Treated Resistance to thermal and mechanical shock Stackable Dishwasher safe This Libbey Gibraltar 12 ounce double rocks glass is perfectly balanced to rest on trays for easy service. It has been treated with Libbey's patented DuraTuff thermal after process for "pressed" tumblers, which gives the top portion of the glass maximum resistance to thermal and mechanical shock. When you see the embossed DuraTuff name on your product, it means you're getting the longest service life in the foodservice industry. Model #: 15243 DuraTuff Treated Resistance to thermal and mechanical shock Stackable Dishwasher Use Traex rack TR-11G with this Gibraltar DuraTuff Double Rocks Glass