Window balancer

A home owner from Skippack, Pa says:
I need 6 window balancers. I'm not sure what brand of vinyl window it is but it is builder grade for a 21 year old house. The metal tape is stamped 540. That is the only identifying number. Can you help me identify what parts I need?
User submitted image of their window hardware.
Profile picture of Paul
Paul from SWISCO responded:
Thanks for posting. Please see our 15-180 pivot shoe, 15-181 support clip, 15-182 bushing, 33-073 screw, and finally the Series 190 coil spring. Based on your stamp, I'd go with the S190-540 . Keep in mind you only need to replace what's broken. There's no reason you can't reuse undamaged hardware.
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