Awesome, i use it for BM 710 and the pivot fits perfectly.
Order made it to me in 11 days installed the hardware from this kit on my genuine griptilian 551-1. Although I had to shorten the clip hardware,and grip screws, the rest of the hardware installed without modification. The pivot hardware is a very tight fit. I recommend being very familiar with the installation and removal of the pivot hardware if you intend to attempt. Thread locker should be applied as well. Axis springs included work great in my ganzo 551 copy.