OSE Quick Change 5" Rail Motor Mount, for 40mm Motor.Designed to speed up the swamping of a motor during a race or if you are just tired of trying to remove the front screws on your motor for maintenance. The front plate is screwed to the motor; the bottom screws can optionally be screwed, but we added a keyway to the top half of the front motor plate and a "key" to the bottom half for added strength to the front plate. This is shown in picture 4. In the rear clamp, we added an O-ring to accommodate variations in motor diameter. Since not all 40mm diameter motors are exactly 40.00mm. Once the coupler is loosened, the motor can be removed in less than a minute. Normally, racers would have to remove the front screws, which could take a few minutes, and more importantly, once a motor is removed from a conventional mount, the motor angle has to be realigned. With only 4 screws, the motor is removed while maintaining the motor angle*. Also features clear access to the front motor vents to allow maximum cooling. Specs: Aluminum CNC motor brackets. Width: 5" (approx 127mm) Motor mounting hole: For 3mm screws Motor hole spacing: 25mm on center Motor applications: Tenshock Motors. Requires: m3 Motor mounting screws x 8mm long. Make sure to use a short enough screw so it doesn't hit the windings. Includes: Front and back mount 5mm-diameter mounting screws for mounting to your rails Oring for rear clamp pn# mc-9262K203 44mm od x 40mm id x 2mm wide