Hey guys - if you want a great trem upgrade for your AX40's here you go. Straight drop-in replacement. I installed it into my AX4 S.U.B. and it works great. Outstanding upgrade and easy. I used the existing posts and the existing nut as it was working fine and the new nut didn't fit. I did use the new string pads which came with the Gotoh. NEW Gotoh GE1996T Locking TREMOLO for Floyd Rose Style R2 | Reverb