The Starrett S436 Outside Micrometer Set includes 12 micrometers, 11 standards, adjusting wrench, in case. The most popular precision micrometers used by skilled workmen worldwide. Anvils sized at .250" (6.35mm) diameter for ease of use on larger work. This model features 0-12" measuring range. Smooth friction thimble for uniform pressure, the combination ratchet and speeder for uniform pressure and quicker adjustment, or a plain micrometer that depends on your own "feel". Recommended for mechanics, automotive service and machine shops, toolrooms, inspection departments and wherever gaging involves a wide range of measurements. SET, 0-12", .001" Grad, Ratchet Stop, Lock Nut involves a wide range of measurements.