This handheld microphone has an integrated multi-frequency transmitter and UHF technology. It is for use with Portable Radio Frequency Receivers [RF-RX1-865/915], with two versions available that respectively work on 865MHz (UK/EU) or 915MHz (USA/AU) frequencies. This microphone transmits sound wirelessly and directly to groups of receivers programmed on the same channel, making it ideal for use in lectures, events, and educational venues. The unit is supplied with 2x AA Alkaline batteries. However, rechargeable batteries can be used to power the unit and charged through the micro-USB charge port.