audio-technica 3MHz band infrared cordless microphone AT-CLM7700TX

Model: Unidirectional dynamic type // Carrier frequency: A: 3.2MHz B: 3.7MHz Battery: Dedicated nickel-metal hydride rechargeable battery Continuous use time (dedicated nickel-metal hydride rechargeable battery): Approximately 10 hours (at output ECO) /Approx. 7.5 hours (at output Lo) / approx. 4.5 hours (at output Hi) External dimensions: Head diameter φ56 x L223mm // Mass: 275g (when dedicated nickel metal hydride rechargeable battery is installed) Compatible with CLM771 series