Review (1/5): Just  a poor and bad copy of original
Those heads look exactly the same as the genuine for half the price but the quality is very bad. They last about 3 month and the grid metal looks a very poor quality. One of them broke and a cutter went trough and wounded deeply my skin.... Those things ARE NOT OEM, just a poor and dangerous China made copy.
I replaced those craps with Original that are working fine....