The retainer case is made of food grade PP, strong and durable plastic will not crack or break, long lasting use. Has a tight locking closure, letting you know your case will not open unexpectedly. These little cases are great for retainers, mouthguards, dentures, etc Holes on the case keeps it well ventilated and your oral appliance dry, inhibiting growth of bacteria during storage. PACKAGING: 1 Pcs