I know it's the annoying question but: Is the arc4 generally accepted as a kosher option?
that's an LOR question for each person, but i asked mine and his principal for foil shavers is that as long as you don't push to close to your skin (signified by irritation/redness on your face) so that the razor nips skin, you are ok. so i try to never push to close and just go with it. shave is pretty good even without pushing.