This is our RCJS 750 SS Electrical box mount for a 550. Use when doing a 650, or 750 engine swap into a 440 or 550 hull, and running 750 electrics, and SX driveline (Either SX hull, or Pump swap with X2 driveline). Allows you to mount the Kawasaki 750SS full electric box to a 550 hull. Installation is clean, and looks factory. 750 electrics have a timing curve built into the CDI, and will out perform 650 eclectics. AGAIN will NOT fit with JS Driveline. Part # AP550-750SS