pete_c
Guru
Pete, is this what you have?
I purchased mine as new old stock; so it was relatively inexpensive (less than $500). My case though was sealed with no conduit openings. I did have to drill a hole into the case for the 3/4"/1" short metal conduit; which was actually most difficult; having to buy a special metal drill bit. It only added maybe 2" of wire to the fuse panel. Ideally though you want to attach these style surge protector right to the side of the panel keeping the wires as short as possible.