---30kg Weight Capacity ---Stronger ball bearing centred wheel with Anti Jump safety clip ---8mm thick wheel with 2mm thick section that sits in the tracking ---Oil filled for smoother operation ---Official replacement for part numbers: 17-4264X-000, ACME 4012 or 4012 - X2 ---PLEASE NOTE: The metal bracket may be separated from the rolling mechanism inside the box for shipping purposes. Simple insert the rolling mechanism back into the metal bracket and press the U shaped flap inwards using your hands or a flat screwdriver. This secures the rolling mechanism inside the bracket. PLEASE NOTE: Following a recent rebrand, these parts are now branded as SpacePro (formerly Stanley). The parts remain identical in size and function with some changes in colour and an improvement to the anti-jump clip which is now grey in colour.