X5-D1 is a single disc dry clutch for use on Raptor in the restricted junior class, mainly purple plate. The X5 series is Horstman's smallest 4 stroke design. The small size moves the rotating mass closer to the centerline of the crank for low inertia. The X5-D1 comes with a billet steel drum with removable bolt-on sprocket. Drum runs truer than a drum with a clip-on sprocket. Another innovation from Horstman a bolt-on sprocket prevents the drum from flexing or moving off axis during cornering therefore power robbing binding is eliminated.