This Free-Hub bearing kit provides everything you need to convert a Jazz diabolo in to one of the smoothest running bearing diabolos on the market. Nearly 2 decades of yo-yo design, research and development put Henry's in the ideal position to make the free-hub system. It consists of two contact-free, sealed bearings which are contained within axle ends and mounted within a smooth, wide roller. The fact that these kits are sealed means that dust and dirt can't interfere with the mechanism, making them run smoother for longer. Very easy to assemble and install, crafted from quality stainless steel. This kit also includes tonal hubs. Packaged in a neat blister pack, ideal for euro-hook shop displays. The set consists of: 1 free-wheel axle with mounted black hub, 1 white hub, 2 aluminium discs (50mm), 2 brass-discs (20mm), 2 aluminium cap nuts.