The Drill Gauge is used to size drill bits in fractional or metric and has a 7 1/2" ruler. The Drill Gauge is made of sturdy plastic and is water, alcohol, oil & grease resistant. It is very informative, but compact and is a user friendly reference tool. Custom color match for orders 2500 pieces or more. 3.5" W x 7.5" L x 1/8" Thick