Bosch's X-Lock Cup Brushes feature the X-Lock mount offer a wheel change that's up to five times faster than conventional interfaces. There's an audible snap when mounting an X-LOCK wheel on an X-LOCK grinder. The wheel mounts properly without the need for a spanner wrench or flange nuts. The wheel is released from the grinder with the pull of a lever. Bosch Cup Brushes are ideal for removing weld scale, burrs and corrosion. Crimped wire cup brushes are made with carbon steel bristles that provide a softer brushing action. Bosch knotted wire cup brushes are designed specifically for angle grinders. The precision-balanced cup virtually eliminates vibration, and they are made with high-quality materials.