The RR1 uses a rear rotary valve intake rather than a reed valve in an attempt to achieve more power. The engine came after the Babe Bee and looks very similar with its anodized, machined extruded aluminum crank case and fuel tank. The power improvement was negligible so Cox reverted to the cheaper easier to build Babe Bee. The engine was made for quite a few years and sold for $6.95. A left and right hand rotary valve were made, as were left hand 6×2 glass-filled nylon props for the RR-1. Some versions have a blue tank, others have a clear anodized tank. There were two versions of the tank back as well, to fit the corresponding tank. It has become a collectors item due to its uniqueness and colors and is worth around $300 in 2008.