Description DIFFERENCE: minimum desk height of 26" is required for the size. Measure your desk before purchasing It is the Original Active Sitting Ball Chair Solution for use at the office, home in the living room, classroom, or the gym. Suburb complimentary ergonomic alternative sitting stool solution for desk sitting and standing desk.^ Posture & Health: Activates back and core support muscles which promotes good posture and can potentially relieve back pain for Adults and children. Comfortable substitute for pregnancy birthing ball, labor ball, or Medicine ball.Perfect for ab engagement, yoga, back stretching, posture workouts, therapy, and physioball balance training routines, also promotes flexible joints for healthy lifestyle.^ Packed: There is a yoga ball with one more air plug , a ball cover,a pump for inflation and also a instruction. Some effort needed for set-up, use included accessories (hand pump /air pump adapter) to inflate inner sitting ball until outer cover is completely filled. ^ Remarks: Before inflating, please open the zipper and leave a 3cm hole for inflation. Please install and use the zipper in accordance with instructions. Please increase the strength and inflate the inner ball to make it large enough.^ Because of the photography and the monitor reason, cannot accept the chromatic aberration the buyer please discretely to purchase.