Double Door Floor Guide, Up to 3 in Thick, Steel, Bright Zinc Finish, Length (In.) 8 in, Height (In.) 8 3/8 in, Width (In.) 4 1/2 in, Depth (In.) 1 1/2 in, Floor Mounting, Steel, Hardware Included, For Use With 450 lb, 600 lb and 1000 lb Steel Track