The Shure PGX2/SM58 Handheld Transmitter comprised of the PGX2 wireless microphone transmitter fitted with the SM58 Microphone Head. The Shure PGX2 transmitter features a multi-function status LED (power, lockout, mute and low battery), automatic transmitter setup, power and mute switch, and has an operating range of 300 ft. It operates on two "AA" size batteries. The legendary Shure SM58 vocal microphone is tuned to accentuate the warmth and clarity of lead and back-up vocals. It is consistently the first choice of performers everywhere.