Just bought a Taurus PT111 at a gun show and love the way it shoots and carries so far. Traded a Kel-Tek PF-9 in on it. Anyway it says "Millenium" on the left side and "PT 111 PRO" on the right side with a serial number of TAM 96378. Is it a current 3rd gen gun? It was new in the box. What are the differences in the 3 generations of making this pistol? Thanks, Great info on this sight ,Rob