Normal Direction

Flip Normals:

Invert the selected normal vectors.

Set Outside/Set Inside:

Recalculate the selected normal vectors outside (Default direction) or inside (Inverted direction). If your object is set to Flat Shading the loop normals will be split, and if the object is set to Smooth Shading then the loop normals will be aligned.

Reset Vectors:

This option resets the selected normal vectors to the original vectors when you started Abnormal.