If you have several brnads of grinders on and, you just need to prepare one type of Trapezoid Plate with 3x9mm holes, these Quick Change Magnetic Adapters will save your money.
Magnetic bottons lock the plates firmly.
For Blastrac/Diamitic grinders
For HTC grinders
For Husqvarna grinders
For Lavina grinders
For Rhino system
For Werkmaster grinders