Highlights: Nylon base, fits Cox doors 1/4"W nylon wheel with 7/16"OD x 1-1/2"H nylon base self-adjusts from 1-7/8" to 2-1/2" in track for smooth guiding of lead door For 1" to 1-3/8" thick bi-fold doors up to 30 lbs. each Top mount - Spring loaded Wheel…