Features:-It adopts an inflatable design. After inflation, the board surface continues to rise and the curvature increases. After deflation, the board surface drops and the curvature decreases.-Designed to relieve discomfort caused by long periods of sitting and poor posture, and to relieve lumbar pain, sciatica and herniated discs.-The support plate is made of environmentally friendly ABS and PP materials, and the airbag is made of oxford cloth and TPU, which is durable and has a long service life.-The surface has 104 bumps and 8 magnets, which play an effective massage role.-The middle adopts a hollow design to ensure ventilation, comfort, and no stuffiness.Specification:Colour: gray&whiteMaterial: ABS+PP+oxford cloth+TPUSize: 21.5*38cm Package In.