The Chin-Up Is One Of The Most Effective Upper-Body Exercises You Can Add To Your Training, Helping Improve Your Strength, Posture, And Physical Aesthetic. This Challenging Body-Weight Exercise Strengthens A Number Of Key Muscle Groups And Can Be Made Easier Or Harder Depending On Your Needs.The Cushion Is Designed According To Human Engineering, Users Feel More Comfortable When Using Three-In-One Assembly Trainer To Save Space; When Users Do The Chin Up Exercises, They Can Choose Different Position To Hold The Handrail To Feel More Easeful; Xl Size Parallel Bars Make Exercises More Comfortable.