Maximum weight: 550 Ibs (minimum height) and 440 lbs ( maximum height). Simple and portable design, but sturdy and good security features, suitable for standard and Olympic sized bars Adjustable to fit your height: range from 40 - 66.5 inch/103-168cm. The barbell stands features spotters for your safety with 14 positions (5cm gaps), more ergonomic and safe, suitable for most people's workout needs Made of solid 50mm steel tube, the squat dumbbell racks stands is lightweight yet sturdy enough for your daily squats and bench presses. Rubber end caps protect your floor from scratching New nuts with blue rubber ring inside for more stability, they may cannot be fully tightened by hand, please use a wrench to fasten the nuts. Please DO NOT tighten the feet of each bracket until last. It's a portable rack set, please make sure you are assisted during heavy training Spotter and lock catch, double fixation ensures your safety. If the pin won't screw into place to attach it to the frame, please switch both pins into the other one to see if it works