This is a Series 159 stainless steel spring for tilt windows. It moderates the operation of your window sash using a specifically calibrated coil spring that allows the window to stay open when raised and remain shut when closed.

• Individually, this coil balance can hold 8-1/2 pounds. This is added together with the other coils to support the whole weight of the sash.
• The weight you need should be indicated as a stamp or imprint on your old spring.
• Measures 3/4" thick.
• Designed to work with a pivot shoe (sold separately).
• This coil balance spring is sold individually, not in sets.
• Can work for either the left or right side of the window interchangeably.
• Coil balances are also known as constant force window balances.