The 019 Intermediate Pivot helps maintain door alignment. Doors 60" tall should use one intermediate pivot. An additional intermediate pivot should be used for each additional 30" in door height (i.e.. 90" door should use two intermediate pivots). For single-acting doors only. Mortises into side jamb and hinge edge of door. For use with 3/4" offset pivot sets. Heavy duty stainless steel needle bearings, stainless steel base material. UL listed for use on 3-hour fire rated doors.