 Pliers have been sourced by a few vendors including the aforementioned Western Forge "WF" tools and Wilde Industries which have a "P" on the tool.Some sockets (notably the 3/4 drive US made units) were made by S-K (coded "X" on the tool).Many major Sears Craftsman items as noted above also have a vendor prefix, which is typically the first three digits before the period or dash in the model number.