These are accessories for upgrading to a 5mm Z-rod, The reduction of edge waviness, makes the conversion a must have, both items have been printed with a 5mm z-rod and the quality speaks for itself.
Make sure to properly update the firmware based on the thread count, the reason there is such a difference in quality is both the number of steps per millimeter of height increase increasing the accuracy, while the step counts become a evenly divisible number as opposed to the use of US standard converter to metric.
Required parts are;
-5mm 0.8 threaded rod
-5/16x3x16 clear tubing
-16mm O.D. 5mm I.D. bearing
- original screw from the stock printrbot zcoupler.