Designed for use as a heavy-duty guide on large sliding doors up to 3-3/4" thick. Slots in the frame allow you to adjust the fit of the doors against wooden walls or posts. Reversible Delrin wheel; can be used on either side of the frame. Offers sturdy steel construction. Meets ANSI/BHMA A 156.14. Adjustable roller. Includes holes for nails and wood screws. Hardened steel bolt for added strength.