Andersen Narroline Double-Hung Sash Balancer 837 is a reliable part designed specifically for Andersen 200 Series Narroline Double-Hung Windows manufactured between 1968 and 2012. This sash balancer plays a crucial role in maintaining the position of the window sash, ensuring smooth and consistent operation every time you open or close your window. It is compatible with various unit models, including 2056 Even, 2452, 2842, 2846, 30310, 3432, and 38210 featuring non-tempered glass, as well as 1852, 1856 Even, 2042, 2046, 24310, 2832, and 30210 with tempered glass. The size 837 balancer is also an effective for earlier models such as 823, 827, and 831. Installed above the upper sash in the head jamb, it fits both the left and right sides of the window. For performance and longevity, it is to replace both sash balancers along with the window side jamb liners during installation. Model Number: 1626037