JGAurora A3S DTI Holder for Bed leveling

Here is a DTI holder to fit the JGAurora.
Details of the use can be seen here.
First home the extruder and set the bed with a slip of paper. Set the DTI to zero and then run through the bed leveling adjusting each corner until the DTI reads zero again.
As adjusting one corner can affect the others run through the operation again to check the level.
I used this Inexpensive DTI https://goo.gl/YexD6u
STL file for the DTI holder https://www.thingiverse.com/thing:2806494
Knobs https://www.thin