The CRL TC21HSVR TOYO Oil Cutter Head incorporates TOYO's TAP technology in which the wheel bore is lined with 8 microscopic cams which work to create a tapping effect as the tungsten carbide wheel scores the glass. This tapping effect drives the score deeper into the glass and lessens the frequency and size of flares during break-out. The 153 degree hone angle is perfect for heavy, thick glass cutting. Due to its unique precision oiling system the TC21HSVR is meant to fit the TOYO TC21 Custom Grip cutters only and is not interchangeable with the TOYO Comfort Grip line of cutters.