The hull numbers are thermally printed on clear waterslide decal paper. They are white with black shadow.  They are sized to fit GHQ models but will mostlikely fit other manufactures as well as Shapeways 1-2400 scale prints.  Unlike the BB & Cruiser sheets there are only 2x of each hull number.  Benson, Gleaves, and Fletcher-class destroyers with hull numbers from 576 through 687.
 
The decal picture is with a GHQ Fletcher class DD for scale purposes.