Gauge Keys include the following sets of incremental dimensions: 1/32” to 1/8” in thickness for letoff, 1 5/8” to 1 7/8” in length for blow distance, halves of the blow distances for damper lift or half-travel, and 1/2" to 5/8” in width for backchecking. A set of Gauge Keys is included in each Regulation Station Package.