Waterproof microphone for security cameras. Operation confirmed. This type is used by connecting to the RCA audio input on the back of the recorder. It can be fixed with screws or double-sided tape. Audio terminal: RCA Power terminal: 2.1mm DC Operating voltage: 12V (center positive) A 12V, 2.1mm DC terminal, center positive adapter is suitable for the power adapter, For example, the following product is inexpensive and good. https://www.amazon.co.jp/dp/B099J97BK1/ If the power adapter included with the security camera is 12V, 2.1mm DC terminal, center positive, You can also share the power with the camera using a commercially available DC power splitter cable. * It's easy to connect, but support is available if you have any questions. * The ballpoint pen is for size comparison and is not included.