Hold 750 lbs Pull Up Bar for Doorway No Screw Portable Adjustable 26-54 inches Door Frame Chin Up Pullup Exercise Sport Equipment Strength Fitness Training No screw fixation. There are two widening anti-skid devices designed on both sides of the pull rod. Installation is very simple, by turning to adjust the length of the bar, apply pressure to the door frame to fix it. Length is adjustable, easily fits most door frames between 26"- 34". Fits standard doorways and is ideal for home, garage or office use. Rotation lock. After the bar body is fixed on the door frame, it is locked by the safety locks on both sides. It can be firmly fixed on the door frame. Supported weight. The friction is increased by adding pressure and anti-skid pads. The maximum support weight of the test is 750 pounds. The test object is an iron door frame. Thanks for you're interest and don't forget to check my other items in my closet.