The complete pro system comes with an original Ergorig, Undersling, and Undersling Riser.
 
Ergorig is an innovative weight displacement system that saves the backs of camera operators without impeding camera movement.  All Ergorig orders come with an embroidered set bag.
 
For sizing, measure from your front hip point to the top middle of your shoulder. If you're less than 20" order a short, more than 20" order a tall. Your front hip point is the part that feels like the tip of the triangle in your hip on the front side that is right around your belt line. Of course there's overlap between the two sizes, so if you're right at 20" either will work.