The BY-M1DM from Boya is a double lavalier microphone, which is suitable for smartphones and (DSLR) cameras. Thanks to the cable length of four meters, you have enough freedom of movement. The special feature of the BY-M1DM is that it is suitable for both smartphones and cameras. With a special button you can switch between these two modes. When you use the BY-M1DM with a camera, the LR44 battery does its job; this gives the microphones their power. A 3.5mm to 6.3mm adapter is included to connect the BY-M1DM to more professional cameras.