The O gauge versions are very similar to the OO Universal Jig. They are intended for use on straight single points either left or right throw.
 
The variants for the DCC iP and the Twistlock motors are a Two-Part Jig. This is due to the fact that the point motor fixing dimensions are in line with the rails and would be impossible to drill the fixing pilot holes from above. 
 
Althouigh the use of the jigs is very easy and straight forward, full instructions with diagrams are included in every pack.