I believe the house was built in 1987. It is a Double Hung Window and I need the right and left sash balance. The model number is 11600-17 and the serial number is d73 7#27 3, 87"
Tom from SWISCO responded:
December 21, 2020
Hello! Based on your old stamp of "7#27," I recommend the 24-737 Andersen sash balance. I am very confident this will work for you as a replacement.