Can anyone help me ID this MSP?

[quasimodo_652]

I'm trying to identify this customer's service panel. There are no markings or labels and I haven't come across one in my years of working in PV. Can anyone help?

Thanks!

 

[curt swartz]

Those are XO breakers. Originally from Square D but they sold the line to Cutler Hammer. They were popular in the 50's Era.

 

[nizak]

Square D XO.

I just changed out a panel a few weeks back.

 

[norcal]

As said by others it's a XO panel, SQ D & Cutler-Hammer both sold them, around here there are subdivisions that were full of Cutler-Hammer XO panels. Replaced by SQ D QO, and C-H type CH, in the late 1950's.