This is the JR RG411BL 4-Channel DMSS Shielded Antenna Park Flyer Receiver. The JR? RG411BL is a super micro size 4-channel DMSS receiver featuring a coaxial sleeve antenna suitable for use with a narrow carbon fuselage aircraft like a DLG glider, as well as small electric powered airplanes. JR Dual Modulation Spectrum System (DMSS) 2.4GHz protocol offers a secure radio link that combines DSSS and FHSS capabilities into a wide-band transmission system that includes high speed response and high resistance against RF noise. One benefit of DMSS is the JR Intelligent Output System (IOS), which automatically selects control signals that need to be transmitted at exactly the same time and delivers the data as one complete signal frame. IOS ensures there is no time delay when commanding servos used for critical functions.