Fits a Guarder frame just fine, but man it would have been really nice if they in some way indicated that this has a huge ZEV trademark on one side. Not exactly ideal for a SAI build...
I wanted to try this out on my WE G17, but unfortunately it would seem that Bell Glocks are different in size when compared to Glocks made by WE. The mag well was too small for my WE G17, even without any backstraps. I managed to MacGyver the mag well on the grip, but it just looked terrible, and would interfere with magazine changes. Only buy this if you have a Bell Glock, and even then why are you spending money upgrade a Bell's externals?