Foxboro RPM Tachometer / Speed Indicator

This unique gage is for measuring speed in rotations per minute from 100-4000 RPM (forward or reverse direction). Size is 2.5" dial face diameter x 3.7 x 1" thick body. T is a select window that is changed by pushing the main shaft down against a spring load until the desired range is found, they the user can lock in the range by turning the knob on the side to the locked position. It works in every range, very smoothly. I believe this to be an early model of the speed indicator by a maker who is still in business today. The condition is good, having lost most of it's original nickel or chrome plating, the case is bare cast metal, no rust. Some staining (or maybe light grease) inside under the dial cystal or clear cover on the dial face (which has some hairline cracks), but the dial face appears to be solid in place and easy to read. A unique tool or instrument for those who collect or use the rare tools!