Lift and cut shavers

Pretty suprised that no one has asked this yet/
Are lift and cut shavers allowed?

Yes.

do you have to modify them at all? need a hechsher. also woukd you mind explaining the reason please? thanks

You do not have to modify.

There is a shield so it is not an issue.

why isnt it mispraiim ceein taar

why isnt it haschasa derech giluach

Because there is a shield that blocks the skin of your face from touching the actual blades. A “taar” is only prohibited when it touches your face. So regardless of how well the shaver shaves does not therefore constitute an issur.