Clemson-class destroyers (along with the preceding Wickes-class) were the most numerous class of destroyers the US Navy had during/before WWII. Of the 120, 48 were converted into auxiliaries and 72 were retained as destroyers. Of those 72, 27 were fitted as Ocean Escorts/Submarine Hunters and operated mainly in the Atlantic.
This product contains 3 of the Escort/Subhunter version (6x 3"/50cal, 2x triple 21" TT, 'K' guns and 20mm cannons) and 4 of typical 1941 DD layout (4x 4"/50cal, 4x triple 21" TT)
http://en.wikipedia.org/wiki/Clemson_class_destroyer
http://en.wikipedia.org/wiki/Wickes-class_destroyer