Searching for 93-1 ALP
A quick learner says:
June 20, 2016
Can't find any markings except on the bottom sash between the glass is stamped: 93-1 ALP. The window is 55" x 33" and the bottom tilts. The side spring thing is encased in plastic. I've included a picture of a bottom sash that is still working.
Tom from SWISCO responded:
June 22, 2016
Hello! It looks like you have an older spiral balance. I think you should consider the Series 600 but there are a couple things you should look into first. The most important detail to confirm regarding your balance is the size of your outer tube. Looking at your second picture, it appears that your balance had a plastic sleeve acting as the outer tube that broke down over time. I would measure its diameter to confirm that it's either 9/16" or 5/8"; if it is, then the Series 600 is definitely what I would suggest.
The other thing to keep in mind is the strength of the new balance. I don't see a color tip on yours so I'm not sure what to recommend. I would weigh your sash on a scale to determine the best option.