Question: What are the rear portion deminions? I need capability of entering a 4 inch emt conduit from the top where the enclosure shall be installed onto the wall.
Answer: Thank you for your inquiry. Here is a link to a mechanical drawing of the unit:
https://www.werackyourworld.com/assets/CategoryFiles/WD-Series.pdf
It appears to have three knock outs on the top of the unit, in the back portion that attaches to the wall. Each knock out can be 1.35, 2.4, 3.53 or 4.53 inches.