This is a precision X belt tensioner for the Replicator 2. It snaps on the rear X rod and rests flush to the left. It is held in place and it's movement tracked by a cable tie. Tension is granularly adjusted with the twist of a screw. It requires; 1 18mm m3 (roundhead is best) 1 16mm long 3mm OD rod 1 3mm x 6mm x 2mm bearing (VXB 623 will do nicely) 1 2.5mm wide cable tie *Note this is not designed for the 2x and I do not know if it will fit one.200 micron 33%fill 2 shells miracle grue. Prep: Bore the screw hole in the main body out to 3mm true and ensure the m3 screw turns freely and hasn't threaded the hole. Press fit (parallel jaw pliers work fantastic) the bearing rod into the T-Joint. Thread the T-Joint hole w/ the m3 (Alternately, you can bore the hole out and insert a threaded female pressfit). Press fit the bearing into the bearing wheel. Feed the zip tie into the bottom of the Xidler body. Prep is done..... Mounting: See video http://youtu.be/BquLty3ShTM