Cushion is 13.5in / 34cm in diameter, large spiky dimples on one side for standing, and very small dimples on the reverse side for sitting. 1 unit of air pump is included in the package for handy and fast inflation. Presented in a nice color box and ideal as a gift. It is suitable for both adults and children, making it a versatile option for home, office, classroom, therapy, and fitness settings. For adults, it aids in improving balance, coordination, flexibility, as well as strengthening muscles and stabilizing joints. For children, it serves as a sensory wiggle seat, providing valuable input to help them focus and stay engaged. Made of nontoxic and heavey-duty PVC. Lab tested, conforms to the safety requirements for toys. Suitable for both Kids and adults to use safely. Instruction: To inflate, the pin from the pump must break through the valve to reach inside of the cushion, or the pin hole would be BLOCKED by the valve wall preventing air to enter. To release the air