Every side has pre-measured holes scored into the plastic for easy feed-through of pipe. Each short side has Eight 16mm, Two 16mm OR 21mm, and One 21mm OR 29mm positions. Each long side has Eight 16mm, and Two 21mm OR 29mm positions.
The bottom has Four non-punched slots with dimensions (190mm x 240mm) for bottom-mounted attachment screws. One short side has vertical slots while the other short side has horizontal slots. Dimensions are on center of slots.
It is also possible to mount the entire box by using the top cover holes. The dimensions (also on the bottom of the box) are 239mm x 346mm.