Panther X - originally created for 20 time World Champion - has been considered the top shooting glass in the world since it's introduction in 2003. Snap Tech lens changing system, zero visual interruption, total adjustability in the frame are just a few of the things that make this model a choice of champions. The difference between a post and a no post model is in the nose piece. A post model has vertical adjustment and is capable of accepting a prescription insert. The no post model is a plano-only version and has perfect site registration with zero visual interruptions.