This is a product designed to reinforce the left side of the Onewheel GT axle. It inserts into the axle, then a screw it tightened down to wedge the two pieces into the inside of the axle. This item was designed to add strength to the weaker side of the axle while adding thermal capacity to help remove more heat from the stator. It is easy to install.
Please note, this part only fits the left side of the axle! The wire harness prevents its use on the right side of the axle. However, the left side of the axle is longer and has more stress on it. Also, most riders ride heel side to the left. This makes the left side of the axle more prone to breaking. However, the right side can still be broken! This product does nothing to prevent the right side of the axle from breaking!