Use this Prime-Line F 2537 Wood Window Sash Spring to repair or replace broken sash cords without removing the sash. Includes 2 sash springs. Featuring a corner mount design, this sash window spring is easy to install and quickly mounts in the upper or lower corner sash against the jamb. This spring sash creates increased friction against the jamb to prevent sagging due to broken or weak sash cords. Constructed of zinc plated steel, these sash window parts are strong, durable, and built to last. This sash spring measures 4-7/8 in. Please refer to the sash window spring line art drawing for dimensions and compare with your needs before ordering (not universal).