This is a Crouse Hinds 100 amp 3 wire 4 pole Arktite plug. Part # APJ10487.  Style 2 grounding.  Check my feedback and buy with confidence.  We have been in business for 30+ years.  As with all my listings, your satisfaction is guaranteed.   We 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.