The Design.The innovative design of the Murkens Gage makes it one of the most rigidbases you will ever use.This rigidity greatly increases the repeatability of your indicator whiledecreasing the number of adjustments necessary during use. The simplicity ofthe mechanism results in fewer moving parts to repair or replace.The overall performance of this gage is most impressive. The Features.* Spring steel front for rigidity.* Hardened -40 screw with extra-long brass bushing.* Blackened for appearance and rust resistance.* Built-in bar for checking squareness.* Hardened bottom with dirt grooves.* Large diameter adjusting knob for sensitivity.* Wrench hole in end of chromed rod for tighteningloosening.* Spring-loaded indicator rod prevents nose-diving.* 7-12" chromed rod for tall work pieces.