Double suction cups are made of thickened rubber, with an 8.66-inch diameter, which provides a larger suction cup area and higher stability.Four height adjustments, which can be adjusted according to your needs, suitable for different people.Sit up assistant device is the best helper in abdominal movement, push up, sidekick, sit-ups, backstretch, elbow plank, hip bridge, crunches and other sports. you can workout at home any time.size: 26x22cmMaterial:Cold rolled steel + high elastic foamcolour:BluePackage Contents:1 x Sit Up Assistant DeviceOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.