With the FUTABA FDLS-1 you double the security in your model by operating two S.BUS / S.BUS2 receivers in parallel. In the event of a problem with the main receiver, the FDLS-1 switches over to the second receiver at lightning speed. Two S.BUS / S.BUS2 receivers are required to use the FDLS-1. Technical specifications Operating voltage: 3.5-8.4V Length: 225mm Weight: 6.5g