Specification Outside diameter: 3 1/ 2 inch (9 cm) Inside diameter: 1 3/ 8 inch (3.5 cm) Material: durable plastic Sizers: 3MO, 6MO, 9MO, 12MO, 18MO, 24MO, 30MO, 2T, 3T, 4T Package included 1 x Size divider (3MO) 1 x Size divider (6MO) 1 x Size divider (9MO) 1 x Size divider (12MO) 1 x Size divider (18MO) 1 x Size divider (24MO) 1 x Size divider (30MO) 1 x Size divider (2T) 1 x Size divider (3T) 1 x Size divider (4T)