ERGONOMICALLY DESIGNED - The double-row support rods of this situp foot holder provide extra downforce and more efficiency. The ab crunch machines high-density soft foam-covered handle regulates traction on the feet and protects the ankles from injuries. GREATER STABILITY - The abs workout sit up assistant devices large single-suction cup which measures 5.7 x 4.5 is made from extra-thick rubber and offers a load capacity of up to 198 lbs. MULTIPURPOSE - Our ab rocker abdominal exercise equipment is the perfect tool to help you perform better situps, sidekicks, elbow planks, pushups, crunches, and much more. You can use this ab workout machine to work out in the comfort of your own home. EXPANDABLE HEIGHT - The crunch bar upper body exercise equipment comes with 3 different height adjustments making this abs trainer at home workout equipment suitable for the whole family. EASY INSTALLATION - This ab machine can easily be installed at home without the need for any tools. Simply place the sit-up suction Cup on a clean, flat surface, prass it down, and push the locking lever down to lock securely in place. Please be aware that suction cup needs to be place on flat clean surface .