This is a mounting plate for a Konnected Pro board (https://konnected.io/products/konnected-alarm-panel-pro-12-zone-kit) with integrated standoffs so the solder joints on the back of the board are not resting against the print.

The mounting holes for the board are sized for M3 screws. I used M3x16 with a nut. The recessed holes are sized and spaced to mount to common dinrail adapters like this one (https://www.aliexpress.us/item/3256804341260304.html?spm=a2g0o.order_list.order_list_main.17.2b541802S3hyxQ&gatewayAdapt=glo2usa&_randl_shipto=US)