Airspeed Indicator, 0-250 MPH, Kollsman 157-046-245, 1930-40's

This Airspeed Indicator displayed airspeed from 0 thru 250 MPH by rotating twice around the dial to indicate accurate speed. As airspeed increased, the pointer rotates clockwise and indicates speed on the inner scale up to 125 MPH, subsequently the speed is indicated on the outer scale up to 250 MPH.

The indicator appears to be either pre-WWII or early WWII, judging from its design. It is a fine specimen given its apparent age.  Measures 3.25 inches diameter and ~2.5 inches deep.