Prime-Line Matte Silver Plastic Bi-fold Door Guide 2 pc

This is a spring-loaded, 3/4 in. square glide or guide in a 3/8 in. plastic base. It mounts on the top edge of a bi-fold door that is 1 in. to 1-3/8 in. thick. To install use a hammer to lightly tap into the pre-drilled top mount hole. Used by Alliance Doors and a variety of bi-fold door manufacturers.