It's a rare occasion when I encounter a set of razor blades that do not cut me, but it has happened. These haven't injured me in all the time that I've used them. Even usual suspects like the sides of the back of my knees and on my ankles have been nick-free.
There are two blades on each razor. They are wrapped with microfine wires. I think these are what are keeping my legs and underarms safe from any incidents. Usually I like the razors with more than two blades, because I think they are less apt to cause razor burn. Tangent: It always blows my mind when another year goes by and they add yet another blade onto a razor.
What I've found is this lowly two-bladed razor does the job well. It has not caused any razor burn. It leaves my skin smooth to the touch. There is a comfort strip enriched with Vitamin E and aloe. I appreciate that, but I don't trust those strips alone to shave with. I use tons of shaving cream.
I find that these last the normal amount of time before getting dull.