Includes ring for compact pocket use and large diameter for easy readout.
One side is fitted with a special dial for exact measurement of straight
lines and curves on technical plans, drawings, blueprints, etc. While the
pointer indicates traced distance in inches, the counter disk registers it
in feet. The second dial measures distances on maps or plans made to scales
of 1/2", 1/4" and 1/8" to a foot and counts the number of full pointer