The NEW 98mm Extended Forward Closure 98mm Extended forward closure Side View of the same The new 98 mm closure above will fit any DrRocket or Aerotech 98mm casing  It uses a special delay element that burns for up to 2 min longer than engine burn out.  Thus giving the user an extra two minutes of tracking smoke.  This the same closure as used in the MRS rocket but it does not have the added.double threads.  Key Benefits 1/4 20  Threaded area at top for attachment of a bolt to secure recovery devices Up to two minutes of additional tracking smoke.  Compatable with any 98mm motor Great for that High Altitude Flights.  Tested with the N-15360 at Balls launch.