Tips on using multiple microphones at the same time:Dear friend, if you need to use two or more sets of microphones at the same time, you need to lock different frequencies. Methods as below:1. Turn off the receiver.2. Press and hold the microphone's power button and the right arrow at the same time. When the microphone screen flashes, turn on the receiver.3. When the receiver's RF flashes 3 times, the frequency of this group of microphones is locked.4. The other microphones are set in the same way, and the frequency of each group cannot be the same.1.WIRELESS MICROPHONES WITH WIDE COMPATIBILITY: Receiver with universal 1/4" plug which works with mixer, PA speaker, and amplifier. Package includes 6.5 to 3.5 adapter makes it compatible with the devices with 3.5mm jack such as DSLR camera, digital camera, laptop, desktop, laptop, iPad & smartphones. For smartphones without 3.5mm jack, please use with 3.5 mm to lightning/Type C adapter (NOT INCLUDED), NOTE THAT: Bluetooth Speaker and MACBOOK are not compatible with this system.2.UHF WIRELESS MICROPHONE SYSTEM WITH 25 FREQUENCIES: Equipped with the latest UHF tech which delivers 25 frequencies, provide more than twice alternative frequencies compared to the normal 10 frequencies systems. You can choose the suitable channel with a lowest electric appliance interference in difference interference situations thanks to twice more alternative frequencies.3.PREMIUM AUDIO PERFORMANCE: Using the latest noise reduction chips and algorithms, 15% noice reduction enhanced compared with the previous generation, it can suppress more environmental noise (road noise, wind noise, etc.), and is more sensitive to human voice input. Equipped with 3 high fidelity microphones provides extended frequency response and superior transient response, suitable for video recording, live streaming etc.4.SMARTER, LONGER, STRONGER AND MORE STABLE WIRELESS LAVALIER LAPEL MICROPHONE: Achieve automatically pairing once the receiver and transmitter power on; with longer battery life up to 4.5 hours continuous speaking; has stronger signal which can operate up to 350 feet and more stable performance with low latency and not audio skip.