This is an Appleton GRT75 or OZ/Gedney GUAT75. 3/4" Explosion Proof Type GUA Conduit Outlet Box.  It is factory new. Call if you need a bigger quantity.  It is equal to Crouse Hinds GUAT26

 I also have most other sizes in my store.  Check my feedback and buy with confidence.  We have been in business for 20+ years.  As with all my listings, your satisfaction is guaranteed.  I can ship same day ups if the order is received before 3:00 pm central.  Check my store for more fittings or contact me for items not listed.