1 Channel. This Sentry code hopping channel receiver operates on short range frequency 433.92MHz and has a range of up to 100 metres (in clear line of sight). The receiver is compatible with code hopping transmitters and up to 32 transmitters can be used with each 1 channel receiver and up to 8 transmitters with each 3 channel receiver. Please note code hopping receivers and transmitters are not compatible french rolling.. Choose from 1 or 3 channel. Surface mounted technology. AC or DC. 3 Amp maximum for 3 Channel / 10m Amp maximum for 1 Channel