The R2104GF is designed for use with the Futaba S-FHSS or FHSS system transmitter. R2104GF Specifications: 4-channels Receiving on 2.4GHz band System: S-FHSS/FHSS system (auto detection) Operation mode: Normal/High speed (auto detection) Power requirement: 4.8V or 6V (shared with servo) Current drain: 30mA (at no signal) Size: 39 x 26 x 10 mm Weight: 8 g Compatible with: T2PL-2.4G T3PL-2.4G T4YF-2.4G T4PL T4PLS T4PV T4GRS T4PX T7PX