56190500 Inner Stone Guard Fits Kuhn Disc Mowers GMD44 GMD55 GMD66One New Aftermarket Replacement Inner Stone Guard for Kuhn Disc Mowers This aftermarket replacement inner stone guard protects the disc mower cutter bar from rock and debris damage during operation. The inner stone guard mounts on the cutter bar between the mowing discs, absorbing and deflecting impacts that would otherwise damage disc blades, blade bolts, or the gearbox. This part applies to early serial number machines verify your serial number