Window Balancers-Proper model to order

Hi there, thanks in advance for assistance identifying the property window balancer for my windows. The trickiest part is measuring the bottom shoe depth. I believe it's 1 1/8 inch, but 1 3/32 could be a possibility. Obviously, those 2 measurements are incredible close. Based upon comparing the various balancers on your site, it appears I need to order a few of the 27" series 395 if I use a 1 1/8" bottom shoe depth calculation. My Atrium Windows are 20 years old now and have had different replacement balancers dropped in periodically as the strings have broken. The photos I'm including are of a balancer that was installed by the builder, so ideally I can order this exact one. I'd love to replace both sides on 6 windows in my house to give all of them a fresh start. I just need to nail down the spec before ordering a bunch of them. Thanks for your help, I sincerely appreciate it! Jay

Thanks for the speedy reply Jasmine, I sincerely appreciate it! I just ordered 2 of the S395-27's, fingers crossed they are the correct spec. Assuming they install with no issues, I'll ordered the other 10 channel balances to complete the remaining windows. Thanks again!