Part that has the spring to slide window

Question

I've attached pictures of one of the bar that  enables the window to slide up & down. Since there are different sized windows in the house, we have found 1840, 2340, 2320 & 1820 stamped in the metal.

Tom · Accepted Answer

This part is called a channel balance. Yours looks similar to our Series 377, which comes with a 19-018 top and 15-005 bottom nylon fitting. As long as those match up then this should work perfectly for your windows.