Prime-Line N 6582 Door Roller, 7/8 in Dia Roller, 1/4 in W Roller, Nylon, White, 1-Roller, 30 lb, Top

Nylon base; fits Cox doors. 1/4 in W nylon wheel with 7/16 in OD x 1-1/2 in H nylon base self-adjusts from 1-7/8 to 2-1/2 in in track for smooth guiding of lead door. For 1 to 1-3/8 in THK bi-fold doors up to 30 lb each.