This is 1/8" thick aluminum plate designed to support our IG42 motors. Use M4x8 screws to mount the motor to the plate. To mount the plate to the chassis, use the IG32 and IG42 Motor Plate Hardware Kit. This plate is used on all of our IG42 SB wheeled robot kits and can be used with our motor mount tube to mount a motor and shaft with a ball bearing. (These are not intended for our right angle gear motors, different adapter plates would be needed).