Crafted for everyday use, Arcoroc Conique Conical tumblers are made from extra-resistant, fully tempered glass. This special treatment ensures they can handle thermal shock without cracking or breaking. And for added peace of mind, even if a breakage occurs, the glass shatters into small, smooth shards for safety. Plus, these tumblers are dishwasher-safe and show no wear or tear even after enduring over 2, 000 cycles in a professional dishwasher.