The PRM90 gearbox is designed for use in pleasure craft where a simple lightweight transmission is required.
The cone clutches for both ahead and astern are mechanically operated and require no adjustment.
The gearbox is purposely built to operate with standard rotation engines i.e. providing a clockwise rotation of the gearbox input shaft when viewed on input. In forward drive the output shaft rotates opposite to input shaft therefore requiring a right hand propeller.