NOTE: This is the new version of this gear - Its not cut like the previous Cold Fusion gear so the whining noise is now eliminated - The Primary Gear is an upgrade/replacement for the Primary Clutch Removal Washer (which removes pounds of rotating mass) that is included in the TB Manual Clutch kit and similar kits. It allows for removal of the entire clutch assembly while removing any chance of slippage - It transfers 100% of your engine power to the clutch and is highly recommend for KLXs/DRZs with huge bores and/or stroker cranks or when racing on pavement. Made in the USA