Plastic cups each with lid and straw. Heavy duty single wall insulation with solid one piece outer body. Threaded PS&AS Lid, with Silicone Gasket Seal, and Reusable Straw included. BPA Free Strong & Durable Plastic (As) | Rinse & Reuse | Large Opening for Easy Filling and Cleaning. Safe to use around the swimming pool, at the beach, and in the hands of young ones. 20oz, 24oz and 26oz is also avaliable