Durable material: the retainer case is made of PP, strong and durable plastic will not crack or break, long lasting useBright colors: comes with 6 pieces retainer cases in nice colors, beige, watermelon red, green, tea green, light blue, white; Dimension: 8.5 x 8 x 3 cm/ 3.35 x 3.15 x 1.18 inchKeep retainer or denture clean: holes on the case keeps it well ventilated and your oral appliance dry, inhibiting growth of bacteria during storage