The Click Rule is an efficient tactile and auditory measuring device that measures up to 12" with accurate increments of 1/16 of an inch. Three 12" extensions allow measurement up to four feet. The Click Rule allows for fast and accurate measurement of wood and tool set-ups as well as for general use. It measures outside and inside dimensions as well as depths of holes 3/8" in diameter and larger. It is made from quality material and is plated to prevent rust. An excellent alternative to rulers and tape measures, it is well suited for any measuring purpose.