Small dong is 5.5 (14 cm ) x 1.5" (4 cm )for gentler exploration. Medium dong is 7" (18cm ) x 1.7" ( 4.3 cm) for powerful sensations. Large dong is 8.5" (22 cm ) x 2" (5 cm ) for deep and intense play. Suction bases provide a secure grip and easy control when attached to a smooth flat surface. Comfortable durable SensaFirm is easy to clean and slippery when lubricated.