●The carbon brush size is 17x10x5mm, with long built-in 37mm copper wire. ●Compatible with BMW R45, R50, R60, R75, R870, R90, R100, motorcycle. Compatible with Bosch alternator. ●Make of good quality carbon and copper, sturdy and durable, ideal replacement for your old or worn one. ●Worn brushes are often the cause of a poorly running motor. Replacing brushes can fix an intermittent motor and can restore a motors electric braking. ●Please measure your carbon brushes to match the size before you purchase.