Vintage PRATT & WHITNEY .500 Holder Base for Square Inspection Gage Block in terrific preowned condition - near if not identical to current Mitutoyo 619055 which retails for near $250 - acquired through the estate of a lifelong Raytheon aircraft aviation master metal fabricator machinist and toolmaker who took exceptional care of his tools - no previous owner markings and nice despite not having been cleaned yet in any way - an excellent find for collectors or to put to use immediately at a tiny fraction the cost of the Mitutoyo - 1/2" thick by 2-5/16" from each tip to the flat or 2-11/16" at the longest point - rare old USA made tool for comparator use as well