As other reviewers have pointed out, the two oblique blades protrude slightly beyond the two smaller vertical blades. Not sure why they designed it that way, but it results in only 2 out of 4 blades making contact with the surface. I've used this on a Bosch router in a router carriage and while the finished surface felt smooth, I attribute this mainly to the freshness of the blades. After 15 minutes of use, I had to clean the racquet of resin and sawdust with a brass brush. And after 30 minutes