Special Features:

Clicks at each 1/16 inch and has raised graduations at each 1/2 inch; 6 inches from the sthe starting end is a shoulder (1/4 inch thick) which allows inside measurements from 6-1/4 inches to 12-1/4 inches to be made; depth measurements up to 6 inches and outside measurements up to 12 inches; outer end of the slide is threaded to receive two 1 inch extension rods; includes two 6-inch rods

Properties:

A graduated measuring instrument of flat tempered steel, to one end of which is attached a right angle piece of metal which protrudes beyond the width of the rule. It is used to measure through holes, hubs of pulleys, to set calipers and dividers, and to measure from points where the user cannot see if rule is even with measuring edge.