Fits Lazer Z & Lazer Z AS Series Models: LAS25KC604 (SN 600000-789999), LAS25KC604B LAS28KA724 LAS28KA724B (SN 670000-719999), LZ25KC524 LZ25KC604 LZ25KC604AS (SN 510000-599999), LZ26KC604 LZ26KC724 LZ27KC524 LZ27KC724 LZ28KC604 LZ28KC724 (SN 370000-599999), LZ27KC604 LZ28KC605 (SN 370000-789999), LZ27KC605 LZ27KC665 LZ28KC665 LZ30KC605 LZ30KC665 LZ30KC725 (SN 600000-789999) 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. High Torque Coil: This OEM Upgrade is 210ftlbs of Torque. Higher Torque Means this Clutch holds Strong Even in the Toughest Cuts. 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. Cool Coil Technology: We use a Proprietary Composite Material Instead of Plastic. This Allows the heat to Escape the Clutch Faster. Less Heat = Longer Life HD Clutches 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 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.