used couple of times, not sure how long the receiver holds charge but it can be plugged in while using via micro usb more details on the screenshots attached Dual UHF Wireless Microphone with Bluetooth Receiver for indoor and outdoor use Over 100ft of range 10 UHF variable channels(CH01-CH10) Microphone use 2 x AA batteries (included); Bluetooth Receiver (Built-in rechargeable battery) Rugged microphone built for longevity Perfect for Karaoke, Speech, Meeting, Performance, Indoor or Outdoor use
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