Please contact us first if you would like to order more than ONE set This USB Wireless Handheld Microphone system produces clear & crisp sound with stable performance the receiver is powered by USB port while the Mini handheld transmitter is built-in with Rechargeable Battery which can last 7 hours. Free you from worries of replacing batteries on the go. Benefited from the 3.5MM AUX earphone Jack on the USB receiver you can monitor real time recording without latency or connect it to speaker that accepts AUX input to project the sound from the microphone well suited for Zoom online meeting & teaching iPhone or Android phone video filming podcasting gaming skype chatting Twitch small conference presentation live speech. Reliable UHF DQPSK technology offer you the mobility and freedom of movement when to do energetic and active performances. Automatic frequency pairing makes it easy to setup. Caution 1: DO NOT run more than 1 set otherwise radio interference will occur. Caution 2: NOT compatible with Facebook Live on phones. Caution 3: DO NOT worry about the high temperature on the iPhone lightning OTG adapter.