Speedometer Drive Assistance

[FATTIRE]

Just bought a new wheel for me M750 as the one I had was wrecked.  I bought a new speedometer drive to fit new wheel as my original one was to small.  What is the name of the metal washer that fits in the grooves on the wheel and sits on top of the wheel bearing?  It is gold in color and allows for the speedometer drive to activate.  Your assistance is greatly appreciated as I can not find the name of it anyplace including the service manual, on ducatimonster.com or here. 

[Howie]

6 0000.62648 Relay drive ring if your 750 is hollow axle, same name different part # for 14mm. axles.

[FATTIRE]

Thanks for your reply. I appreciate it.  Now I can buy one and get my beast back on the road.