 GX4 XL. Well, people like the longer barrel for velocity. They like the longer barrel for Accuracy and you're gonna get that with a longer barrel across the board But if you go with this it has a 13 round mag and 11 round mag additional backstrap But they did a nice job and they kept the same trigger now. I measure this trigger right at Five and a quarter pound flat trigger Nice crisp break Five and a quarter pounds with a reset that I put several rounds through this and I had no problems whatsoever