The DS-KD-ACW3 is the three-module surface wall mounting bracket for Hikvision's DS-KD8003 modular door station range.
Surface mounting fixes the panel to the face of the wall rather than cutting a recess, which is often the only realistic option on solid brick, stone or a period frontage, and the quicker one on retrofit work. The angled rain shield keeps direct rainfall off the camera lens and call buttons, which matters more the larger the panel gets.
Three-module size takes a DS-KD8003 camera module plus two of the keypad, card reader, nametag or display modules — the build you would expect on an apartment block or commercial entrance where visitors and residents each need their own route in. Any unused slot should take a DS-KD-BK blanking module. For a recessed finish, use the DS-KD-ACF flush range.