Series No. 52-248 offers Fowler standards of fine quality and accuracy. A variety of sizes covers a range of measuring applications. • Hammertone blue baked enamel finish • Microfine graduations on satin chrome finish and carbide tipped measuring faces • Ratchet stop thimble for exact and repetitive readings • Spindle thread is hardened, ground and lapped • Anvil & spindle hardened and precision ground with microlap finish on tips • All micrometers meet or exceed U.S. Federal specifications for accuracy • Includes a wrench and case