This is from FN
I believe the FNP45 tac started out as their first model and then they came out with the 9/40 model and it was the FNX tactical then FN updated the 45 model and it is now called FNX45 tac
"The FNX-45 will look and feel very similar to the FNP-45. Most of the design enhancements were mechanical for improved reliability and endurance. The FNX-45 will come with 3 magazines (new design and not compatible with the FNP), all 3 will be 15 round like the current Tactical and Competition. The pricing should be similar to the FNP-45."