The metal portion is 21 inches long, not including the plastic ends. The metal portion is 0.5" wide by 0.625" deep.
The stamp reads "20 5 IW CMC 7".
It is for a Milgard, single hung, non-tilt window. The portion of the window that it lifts weighs 15 pounds. The actual dimensions of the window are: 27.25" wide by 23.25" tall by 1.375" deep, including the frame, but not the latch, or handles. The actual pane dimensions are: 24" wide by 19.625 high. The frame is white vinyl.
It is a double pane window and was made in 2004, or 2003.
![User submitted photos of their Milguard window balance](/images/pictures/2012/08/6163.jpg)