Before purchasing, ensure your door frame width is between 29.5-37 inches (75 to 94 cm). This chin up bar is not suitable for frames outside this range. The door frame must be wider than the anti-slip pads at both ends of the bar To ensure safety, the manual specifies a maximum load of 297 lbs (135 kg). Testing shows the product can handle up to 744 lbs (337.5 kg) of instantaneous load, meeting a 2.5x safety factor. However, the pull up bar's capacity also depends on the usage environment. Users should strictly adhere to the 135 kg limit No Drilling, No Traces: The pull-up bar uses innovative fixative technology to stay in place. It features two large 6.5 x 1.8-inch PVC mats for added friction and stability. Four metal fixed points connect the base and bar, ensuring a secure, fall-proof design even under heavy loads Heavy Duty Construction: Our Pull Up Bar supports up to 440 lbs (200 kg) with its 2 mm outer and 1.5 mm inner steel pipes. This pull-up bar built to last without deforming or breaking, ensuring durability for your home gym. Note: Longer use distances may reduce the load of chin-up bar Upgraded Mechanic Lock System: This push-up bar features a new 360-degree rotatable dual gear lock on both ends to protect the bar from loosening. The doorway exercise bar has passed extensive testing, ensuring safety and sturdiness for confident use Easy Installation: Install quickly with detailed instructions, a video guide, and arrow markers on the chin-up bar. Spirit levels on both ends ensure correct setup. Ensure your doorway or wall is solid; avoid ceramic tiles, glass or non-solid doorframe. Note: Verify the marked rotation direction; reversing it may cause locking Integrated, Extensible Structure: Unlike most 2-section foam bars, this doorway pull up bar features an ultra long, integrated anti-slip cotton handlebar for a flexible grip. It's sweat-resistant, odorless, and durable. Twist the bar to adjust its length from 29.5 to 37 inches (75 to 94 cm) for various workouts like pull-ups, sit-ups, push-ups, stretching and more