Stay Roller, Zinc, For Use As A Guide On Large, Sliding Doors, Mounts To Concrete Floor Or Apron, Delrin Bearing Wheel Rolls Easier & Lasts Longer Than Many Other Steel Bearing Hangers, Includes Heavy Duty Stay Roller & 3/8" x 4-1/2" Lag Screw With Expansion Shield, Meets ANSI/BHMA, A1S6.14, Boxed Loose.