Michigan Wheels XHS II Xchangeable Hub Propeller Series offers high performance and versatility. The exchangeable hub kit has a Delrin cushioned sleeve that absorbs impact and stress caused by shifting gears and is designed to spin under significant impact to protect your lower end unit. For use with the Vortex and Apollo Prop Housings, the XHS II Hub is also designed to be interchangeable with Mercurys Flo-Torq II hub system, making it a great choice for a replacement or spare prop.