Can be used on most single or double hung windows. Heat treated high tension steel spring. The FS100 top guide has a 9/16 inch wide nose and the bottom FS151 guide measures 15/16 inch from tab end to tab end. 5/8 inch aluminum channel housing. Compare old guide ends and note their dimensions to order the new guide ends. Must select the top and bottom guide ends that are sold separately. Prime-Line part H 3740 riveting tool can be ordered separately for installation of guide ends.
