replacement block and tackle balances

Question

Hi there,
First off, thanks for reading! I'm a homeowner looking to replace my block and tackle window balances. Here are some specs:

marked "13 4 FR CALDWELL"
for a vinyl thermopane
the string broke on one side--I assume I should replace the balances on both sides?
non tilt window
the metal rod itself is 14" long, 9/16" deep, 1/2" wide at the back (the front is 5/8" since the edges are rolled out)
the channel shoe is 1-1/16" deep, 15/16" wide at the widest part, and 9/16" wide at the narrower back side.

Please advise as to which balances I should buy, and please, quote pricing.

With warm regards, Madelyn

User submitted photos of a window balance.

Paul · Accepted Answer

Thank you for the photos and dimensions. They are very helpful. You will need our S385-14 side load balance. The spring weight option for "13 4" is 1340 for a sash weight range between 11-12 lbs.