This sits up bar must be used on smooth or flat ground (such as tiles, marble, wooden floors, etc) without textures or uneven and coarse surface.Any uneven ground, no matter how minor it is, will still affect the stabilization of the suckers.FEATURES:1. Small size, not occupy space, lightweight for easy storage.2. Easy Installation: The sit-up equipment is easy to install and remove without any tools. It suits for smooth and solid floors.3. A button switch, start three seconds. Waterproof and moisture-proof, safer to use.4. Can be Mix and match with yoga mat/fitness bandsSPECIFICATION: Double Suction Sit-ups Assistant Device Material: foam + stainless steel tube+rubber Size: see the picture Weight:0.85kg Weight capacity: within 330Ib.STEPS OF INSTALLATION:Step 1. Choose a smooth ground to use, and avoid the gap in the groundStep 2. Please use a wet towel to clean the floor and suckers before installationStep 3. Mind the whole surface of suckers attached to the ground when pressing itStep 4. Take off the plastic switch buckle and drag the suckers to ensure complete The sit up bar with advanced two-row support rods that provide greater heel power and double efficiency; High density soft foam-covered handle can protect the instep from pain. The enlarged rubber suction cup enhances the suction power to the ground, more stable and durable. The spring clip of the abdominal device has a four-position height, Through the spring snaps freely adjust their comfort level, just have one to fulfill the training requirement of your whole family. Without any tools to install, the sit up bar's with 12cm bottom sucker, just need to find a dry and clean flat ground, then put down the sit up bar on the ground,pull down the lock, finally adjust the gear position. The sit up bar can be used at home or in the office to shape your body and trim your waist. It is very suitable for exercises such as sit-ups, push-ups, side kick, sit-ups, backstretch, elbow plank, belly movement and other sports. Perfect for tiles floor concrete, cured or any other smooth floors.