Vermont Class ZZ Trilock Plug Gage AssembliesVermont Class ZZ Trilock Plug Gage Assemblies When you need to inspect large diameters, Vermont's line of Trilock Plug Gages are your best solution. These GO NOGO Plug Gage Assemblies include a Plug Gage member on each side, and are attached to the Trilock handle with mounting bolts. Included with the pricing is 1 line of custom marking, up to 25 characters. When ordering, Select Size Range from pulldown menu. After order has been placed, we will