The 1.65 is not a "standard" gap they offer, but after a bunch of research, that's the one I decided on. FWIW, they let me know that if I chose a nonstandard gap, they wouldn't accept a return of it. I don't know (but would like to know) what the max that he can make is. I prefer very efficient razors. This is only my second shave with this razor, though, so just getting to know it.