Futaba 2.4Ghz Receiver R7308SB S.BUS/HV FASSTest. (This receiver supersedes the R7108SB) FASSTest 2.4GHz Bidirectional Communication System. S.BUS2 – 8 channels for conventional system receiver. Features: S.BUS2/S.BUS system. High Voltage 3.7V – 7.4V (Voltage Range 3.5V to 8.4V). 2.4Ghz FASSTest. 8 Channel conventional system. Weight 11.0 Grams (0.39oz). Dimensions – 24.9 x 38.8 x 14.3mm (0.98 x 1.53 x 0.56″).