That looks like a slicker, which could be painful. For the face, I prefer to use combs, for safety, comfort and effectiveness. I use combs on the tail too.
My favorite comb is the Chris Christiansen #6 buttercomb for face and legs. It is pricey, but I love that it is lightweight, the teeth ends are just the right sharpness, and it is easy to manipulate.
Combs & Handles
Any good, smallish metal comb would work.