Ideal for people who choke easily or cannot tilt their heads back due to neck injuries. Useful for children who have cerebral palsy. The cutout fits comfortably around the nose when drinking. The 2-7/8" (7.3 cm) wide opening allows the therapist to observe the liquid going into the clients mouth. The blue tumbler is made of a rigid, hard plastic. The clear tumbler is made of flexible polypropylene plastic. Three sizes are available: 4 fl. oz., 8 fl. oz. and 12 fl. oz. (118 ml, 237 ml, and 355 ml). Household dishwasher and microwave safe.