This is an OZ/Gedney LBH-0507 1/2"-3/4" Hazardous Locations Pulling Elbows. Item has 3/4" hubs, but comes with 3/4"-1/2" Reducing Bushings. Equivalent to Crouse Hinds LBH20 and Appleton ELBD75. Factory box comes with 2, so if 1 is purchased, it will come with no box. 

 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 3:30 pm central.  Check my store for more fittings or contact me for items not listed.