1、Equipped with an easy to use inflation valve, convenient inflation and deflation, it quickly responds to the comfort needs of different scenarios. 2、Ergonomic designs to release pressure, ensure evenly stress. 3、Soft surface designs, moisture absorption as well as breathable. 4、The inflatable cushion is lightweight and portable, suitable for use at home, in the office, and on the go, providing comfortable support anytime, anywhere. 5、Different sizes can be used in different ways, meeting your needs. Item Type: Inflatable Seat Cushion Material: PVC Optional Type: R200, R250, R300, R350, R400, R450 Inflated Size: R200 Outer Diameter: Approx. 18cm / 7.1in, Inner Diameter: Approx. 7cm / 2.8in, Thickness: Approx. 4.5cm / 1.8in R250 Outer Diameter: Approx. 23cm / 9.1in, Inner Diameter: Approx. 10cm / 3.9in, Thickness: Approx. 7cm / 2.8in R300 Outer Diameter: Approx. 27cm / 10.6in, Inner Diameter: Approx. 11cm / 4.3in, Thickness: Approx. 8cm / 3.1in R350 Outer Diameter: Approx. 32cm / 12.6in, Inner Diameter: Approx. 13cm / 5.1in, Thickness: Approx. 9cm / 3.5in R400 Outer Diameter: Approx. 36cm / 14.2in, Inner Diameter: Approx. 15cm / 5.9in, Thickness: Approx. 10cm / 3.9in R450 Outer Diameter: Approx. 40cm / 15.7in, Inner Diameter: Approx. 16cm / 6.3in, Thickness: Approx. 11cm / 4.3in Inflated Size Outer Diameter Inner Diameter Thickness R200 18cm / 7.1in 7cm / 2.8in 4.5cm / 1.8in R250 23cm / 9.1in 10cm / 3.9in 7cm / 2.8in R300 27cm / 10.6in 11cm / 4.3in 8cm / 3.1in R350 32cm / 12.6in 13cm / 5.1in 9cm / 3.5in R400 36cm / 14.2in 15cm / 5.9in 10cm / 3.9in R450 40cm / 15.7in 16cm / 6.3in 11cm / 4.3in R200 Diameter: Approx. 200mm / 7.9in Auricle, wrist, heel, ankle, etc R250 Diameter: Approx. 250mm / 9.8in Shoulders, arms, legs, etc R300 Diameter: Approx. 300mm / 11.8in Face, arm, leg, helper bone, etc R350 Diameter: Approx. 350mm / 13.8in Face, legs, elbows, etc R400 Diameter: Approx. 400mm / 15.7in (of thin people) back, hips, hip bones, etc R450 Diameter: Approx. 450mm / 17.7in (heavier people) back, hips, hip bones, etcSizeDiameterR200200mm / 7.9inR250250mm / 9.8inR300300mm / 11.8inR350350mm / 13.8inR400400mm / 15.7inR450450mm / 17.7in 1 x Inflatable Cushion 1 x Inflator (Random Color)