1500LBS CAPACITY: The 1.25”/32mm thick exercises gymnastic rings are made of birch wood, which is a natural material used for making premium sports gear. The pull up rings have great weight capacity up to 1500lbs/680kg, secure and durable. WIDER NUMBERED STRAPS: Our 1.5”/38mm double-layered straps are wider than the competition, so they are safer and more durable. The easily adjustable straps with numbered loops ensure that the training rings are always at the same height. LOCKED CARABINERS: The carabiners simplify the installation by clipping onto the strap loops, and then locked by the screws for safer workout experience. With the screw-lock carabiners, you can easily and freely adjust the rings’ height on the 9ft long straps.