polyester Unique Design: This hopping ball outside features a soft plush cover and the inside is eco-friendly rubber. The crocodile design is easy to attract kids' attention. Motor Skills: By grasping the handles and bouncing on the gator, little kids can learn how to maintain balance. It also helps burn off extra energy and makes exercise fun. Easy Inflation: Take out the inserted white air stopper; insert the air pump and inflate the hopper to a proper size; then replace the air stopper into the hole quickly. Play Anywhere: Suitable for summer vacation, parties, classrooms, indoors, outdoors, and more. Easily deflates for storage or travel. (Manual air pump included)