10 inch magnetic disk with a half inch hole in the centre.
This magnetic system makes changing from one grit to the next extremely easy, the magnetic base plate stays in place, while the support plates are quickly and easily changed during the grinding/polishing sequence.
(1) If a aluminum or other Non-Ferris Backing Plate is used adhesive ( not supplied) will be need to attach the magnetic plate to the master plate.
(2) If a metal or iron master lap is used then no adhesive is needed. The magnet will do its job holding firmly in place.