HD Clutch es are designed at HD Clutch and Assembled in the USA. Higher Torque: 210 ft-lbs. We add a few more windings to our coils to provide the maximum gripping strength to prevent damaging micro-slipping during tough cutting conditions. The HD Switch BIGBearing design addresses the #1 reason Clutch es fail with a larger tougher pulley bearing. Machined Billet Pulleys: It is easy to damage formed pulley and damage (even a small stone nick) damages the belt with every rotation. With our Billet Pulley design, we include a snap ring so the bearing is replaceable, making this Clutch rebuildable. Clutch es all run very hot; we use a composite material instead of plastic to allow the heat to dissipate much faster. This makes the HD Clutch run much cooler; extending the bearing and Clutch life. HD Clutch wrote the Bearing specifications to include Premium C3 Rated Bearings and high temperature rated synthetic grease to combat heat. Less Heat = Extended Life.