The Purple C-Stat compliments the Green support to further improve usage in "Correlation" and "Function" modes especially where there is no tooth adjacent to the prep. This support is best used when there is no tooth distal to the prepared tooth or there is a stand alone tooth. The long rear (mesial) extension of the support allows more surface for indexing. Engaging up to two mesial teeth gives a more sure index to prevent undesirable rotations that could lead to misalignment, inaccuracy, or failure of the correlation process.

 The distance between the camera lens and the occlusal surface should be 4-5 mm. 

Use the Purple C-Stat for long mesial indexing