The BOYA BY-WM4 Pro K2 is a 2.4GHz wireless microphone system consisting of a belt-pack dual-channel receiver and two belt-pack transmitters, which are compatible with smartphone, DSLR, consumer camcorders, PCs, etc. Dual-channel Receiver Delivers Two Sound Sources Simultaneously Equipped with a dual-channel wireless belt-pack receiver, BY-WM4 Pro K2 wireless microphone system is able to captures two sound sources and delivers both of them to your recording devices simultaneously.