Some old DEC devices used to connect console ports of servers. Didn't need it per say but also didn't need to spend $3k on multiple new console routers.

Was an old isp/mobile carrier so could find all kinds of old stuff. Even the first SMSC from the 80s (also DEC, 386 or similar cpu?) was still in it's racks because they didn't need the rack space as 2 modern racks used up all the power for that room, was also far down in a mountain so was annoying to remove equipment.