A window balance is a device that uses a spring to counterbalance a window and keep it in place. When you open a window, the spring contracts to hold it in the desired position, and when you close it, the spring extends to assist in closing it effortlessly.

There are two primary types of window balances: coil spring balances and sash balances. Coil spring balances use a coiled spring, while sash balances use a spiral balance system to counterbalance the weight of the window.

To select the correct window balance, you should consider the weight of your window and the type of window frame you have. Consult with a professional or refer to the manufacturer's recommendations to ensure proper selection and installation.

Installing a window balance requires some tools and technical skill. Typically, you'll need to remove the old balance, measure the window and choose a suitable replacement. Refer to the manufacturer's instructions or consult a professional for proper installation to ensure optimal functionality and safety.