1.NO Screws & NO Drilling.Please watch our installation video before you install this pull up bar. You only take minutes to set it up and remove it on the door frame. Just rotate the pole to press against the door frame. Pay attention to DO NOT use the pull up bar doorway on glass door, hollowed door or other fragile door frame.2.Safety lockwill prevent the pull up bar from rotating during use, which make sure the security for yourself. Our doorway pull up bar allows you to perform a variety of upper body strengthening exercises, such as pull ups, chin ups, sit ups and leg and knee raises.3.Customize length for an easy fit in most door frame. Suitable for standard doorway, perfect for home, garage or office use. Max. Support: 150kg/330lbs.4.Different from other foam handles, this handgrips are made of high-elasticity rubber and nylon, with the features of Non-Slip, Non-Toxic,non-Smell and also very comfortable.