The Gem Sound GMW62 is a low cost wireless microphone system that includes two headset microphones and two lavalier microphones. It comes with a rugged VHF receiver with individual volume controls, and 3 1/4 connection cable. Microphones include an on/off switch, and operate on one 9V battery (included). Comes with two transmitters that accommodate either a lapel or a headset.This set comes with four mics, but you can only run two at a time. They receive on different frequencies, two at a time, so you can have one headset and one lavalier, two lavaliers, or two headsets. Two performers can switch between lavalier and headset on the fly. Amazing price for a rugged wireless microphone system.Each transmitter operates on a single frequency. This item is the EF frequency. If you want to run multiple systems, there are four sets of differing dual frequencies.