Box end/combo identification help?

[Zevadyah]

Dad's friend brought over this combo wrench with a regular box end, and a weird hex end. Was wondering if anyone knew what the hex head end would be for? It measures 1-3/8" on that end, didn't measure the box end. No markings at all on it

 

[PBCampbell]

That one is a head scratcher.

 

[2oolhound]

for large allen head security bolts?

 

[Al Borland]

Maybe a bung wrench of some sort?

 

[gtsgarage]

Maybe a bung wrench of some sort?

Agreed. Pipe plug maybe?