Keep your pets active and healthy with our Hamster Exercise Ball. Perfect for hamster and mice to maneuver with ease - it is ideal for keeping your hamster or mouse safe while cleaning out their home. Size: 7 inch. Care and use: Ensure it is big enough for your furry friend. Assemble the exercise ball by simply twisting the upper half and lower half in opposite direction and ensure the slots are aligned and lock properly. Open the door by twisting anti-clockwise and close it in opposite direction. Use the exercise ball on a flat open area. Clean with warm soapy water before and after use and dry thoroughly.