This appears to be a new part. It was in a drawer marked "new parts". There is a slight chance it was used a little bit because there are marks around the 4 mounting screw holes but that could be because it is was probably shipped with a junction box. It is very close to brand new.
New these outlets are around $1000.
It is a Russell & Stoll Co. Inc part (Russellstoll). Also know as Thomas & Betts (Thomasbetts).
Part number 7324
60 Amp rating
Can be used up to 600 Volts AC or 250 Volts DC
These plus are used in industries, schools, and hospitals. They are also excellent for welding shops that use very heavy duty welding machines. This outlet can be mounted right to the back of a welder and make an extension cord or on the wall as a way to unplug it. Many of the older heavy welders get wired right in to a disconnect switch because anything over a 50 amp outlet is not easy to get.
This outlet is ideal for 3 phase welders and other machinery.
This item came from a closing down factories extra parts cabinet.
It is sold as-is with no returns.