Coverage from 12 to 20 feet with one door, adjustable every 24" with pre-drilled holes, customizable to fit any opening by drilling additional holes. Heavy collar hinge prevents door from sagging for years. Visibility ensured day and night with reflective decals on the door. 2 in. 18 gauge high strength steel. Standard plated lockable chain, heavy duty collar hinges make theft or removal of the door difficult. Requires smaller posts than most doors.