The DS-KD-M is the Mifare card reader module for Hikvision's DS-KD8003 modular door station range, fitting the same frame as the camera, keypad, nametag and display modules.
It lets residents and staff present a card or fob to release the door, rather than calling through to an indoor station and waiting to be let in. In practice this is what turns a video intercom into a working access control point for the people who live or work in the building, while visitors still use the call button or keypad.
Requires a DS-KD8003 camera module as the host unit and a mounting bracket to suit the build — DS-KD-ACF for flush installs, DS-KD-ACW for surface mounting. Pairs naturally with the DS-KD-KP keypad where you want both card and PIN entry.