Fits: TimeCutter, Time Cutter SS5035, SS5000, ZS5000, SW5000, MX5075, MX5075T, MX5000, SWX5000, 5000, 5000C, MyRide 50" Fits TimCutter & Quest Model Numbers: 74635, 74637, 74638, 74660, 74661, 74680, 74688, 74694, 74695, 74730, 74731, 74732, 74772, 74773, 74775, 74790, 74795, 75750, 75750W, 75751, 75753, 75755, 75755TA, 75755W, 75759, 75761TA. Fits Quest Models: QTE691KA501, QTE708GEM50200, QTE735KC01, QZE725GKC50200 High Torque Coil: This OEM Upgrade has 130ftlbs of Torque (OEM is 105ftlbs). Higher Torque Means this Clutch holds Strong Even in the Toughest Cuts and Prevents Overheating caused by slippage. BIGBearing: The Pulley Bearing Takes a lot of abuse and is often the first thing to fail. We use a Larger Pulley Bearing for a much longer life. We designed our Billet Pulley with a snapring making the bearing replaceable. Tough Billet Pulleys: Billet Pulleys Reduce Belt Wear and Maintain Perfect Blade Speed. Our Billet Pulley Design uses a Snap Ring and Allows for Bearing Replacement. HD Clutches are designed at HD Clutch and Assembled in the USA. Higher Torque: 130 ft-lbs (OEM is 105 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 clutches 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. Clutches 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.