Starrett, 55946, 1 Inch, 5/8" Ratchet Stop Thimble, 0.235" Dia x 1-1/4" Long Spindle, Mechanical Micrometer Head 5-1/2" Long, Accurate Up to 0.0001", Flat Spindle, 0.4999" Dia x 3/4" Long Stem, Steel Measuring Face