This sash lift (for raising a window) has the Art Deco style, and therefore, dates from the 1920s to the 1940s. It was placed at the bottom of the window so one could lift the window with three fingers. It is made of stamped steel and then coated with a dull brass finish.
The lift measures 3 3/4 inches across and 1 5/8 inches vertically. The finger depth is 3/8 inch. It is fastened to the window by two screws or brads from inside the finger indention.