window balance coil spring

Hey there. This is a 15-087 Coil Balance Shoe and 16-031 Mounting Bracket. This system works with Series 180 Coil Balance springs. A '10' stamp on the housing might indicate you need the S180-10 10 pound spring; but stamps on the housing of this system aren't always reliable to go by, so I'd weigh the window sash just to be safe. The video below explains how that works. Let me know if you have further questions.

Series 180 coil balance diagram

No problem. Let us know if you have further questions.