Norton 1601 Drop Plate Compatible with 1687, 1688, 1688C - Perfect for Industrial Grinding and Metalworking Applications

The door closers offer proven quality, performance and
reliability unmatched by the competition. A staple in the industry,
these ANSI/BHMA Grade 1 closers are designed for exterior or interior
doors. A full complement of regular and heavy-duty arms, brackets
and options make the 1600 Series closers ideal for virtually any
medium traffic, commercial application.

• 1688 Drop Plate: For use where a
  overhead door holder prevents normal top jamb mounting.
  This places the center line of the arm mounting screws at
  3-1/2" (89mm) from the top of the door.
• Overhead Door Holder - 1687
  Drop Plate: For use where the ceiling clearance is between
  1-3/4" and 2-5/8" (44 and 67mm). Or for use where an
  overhead door holder prevents normal top jamb mounting.
  This places the centerline of the arm mounting screws at
  2-1/8" (54mm) from the top of door
• 1688 Drop Plate: For use where a narrow
  top rail prevents the closer from being mounted directly to
  the door surface. This drop plate can be used to mount a
  closer on a top rail as narrow as 3-1/8" (79mm) in height for
  1600BC or 2-1/8" (54mm) for 1680BC.