Keller Sash Lock, Sliding loaded Window Latch

Keller Extruded, Spring loaded Sash Lock.

Latch Fits the old style Single hung aluminum window.
The 9/16 diameter Spiral balance rod was covered in a gray plastic with a flat shoe that screwed into the bottom of the sash.

Priced and sold each.

This product is similar to or the same as the following part numbers in these brands:
Strybuc Industries: 50-626