The Vivaldi Wine Glasses by Strahl are made from high-quality polycarbonate, an engineering resin with exceptional strength and resilience. It has the weight, clarity, and brilliance of crystal, but is unbreakable, microwave-safe, and dishwasher safe--guaranteed for up to 2000 domestic dishwasher cycles (dishwasher safe, top and bottom rack. If hand washing, use non-abrasive materials). Its insulating action helps keep cold drinks cold, hot drinks hot, and it doesn't leave condensation rings on the furniture. These are engravable, please specify Interlocking, Times Block, or Old English fonts and First LAST Middle initials, or name can be engraved if you prefer.