The 4 1/2" back up pads with a central locating button are designed for use with 115mm surface conditioning discs.
SCM discs are supplied with a 10mm centre hole which allows for simple location on the back up pad. The location pin eleiminates disc vibration and improves surface conditioning disc life as well as reducing back up pad wear.
For centralising surface conditioning discs on 115mm / 4 1/2" angle grinders
Back up pad - 115mm x 10mm location pin with M14 thread
Fits on 115mm angle grinders