Composite drive shaft assembly. This driveshaft is assembled with 316 stainless steel hardware and hubs. The Max HP at a 2.0 Service Factor is 51 at 1,800 RPM and 43 at 1,500 RPM The max DBSE (in.) is 77 at 1,800 RPM and 84 at 1,500 RPM. Custom bores are included with purchase in the standard range of bore sizes. Larger bores are available at additional cost.