The LinQ series from Onis, may well be the ultimate high-end stackable glass. Naturally, it has all the functional qualities you’d expect: superb stack ability, the versatility to measure up in any surroundings and the Xtratuff strength to withstand the roughest treatment time and time again. Onis Xrtratuff – An additional heat treatment process targeted at the rim of the stemware and tumbler products. Increasing the resistance to thermal and mechanical shock resulting in a very strong glass with prolonged life in service.