Full Concealed, heavy duty No door inset, flush mount 48" door width maximum 450 lbs. door weight maximum Average weight per unit = 11 pounds Fasteners: 12-24 X 7/8" undercut self drilling, thread forming tek machine screws Fire Rating Approved for use on metal swinging type fire doors rated up to and including 90 minutes (Specifiy "FR" option for 3 hour rating) Approved for use on wood swinging type fire doors rated up to and including 60 minutes (Specifiy "FR" option for 90 minute rating)