GOODELL-PRATT NO 31 DEPTH MICROMETER ORIGINAL CASE.  Measures depths from 0" to 3", 2-1/2" base, contains 3 measuring rod-only 2 shown in pictures, 1 is contained in the micrometer, marked GOODELL-PRATT COMPANY GREENFIELD MASS. MADE IN U.S.A., thimble is calibrated in THOUSANTHS, comes in its original velvet lined leather case, a 1911 Goodell-Pratt catalogue listed the case as $.75 extra, the tool was $4.50, tool looks like NEW OLD STOCK FINE, case is also FINE, rare in this condition for age.  HAPPY BIDDING!