MartinRangers VHF WM300H Dual Rechargeable Wireless Microphone Fixed Frequency 170-216 MHz Output Connectors: one 1/4" unbalanced output jack Operation Range: 150Ft (50M) within line of sight Operating Frequency: VHF For Charging both handheld transmitter, please make sure the receiver is OFF (cord still plug to the wall). Only one handheld will be charge if the receiver is On.