My CNC is powered by a Makita router with only a 1/4" collet, so when I began shopping for a spoilboard surfacing bit, I was limited in my choices. Yes, there are spoilboard bits for under half the price of this one, but for the most part, you're getting about 1/4 or 1/8 of the longevity you'll get with this set.First off, having removable cutter carbides allows you to rotate them 90 degrees when they get dull or should one get nicked. This alone gives you 4x the cutter life of a fixed-cutter bit. Now add the fact that you have two sets of cutters, and that gives you another 4x for a total of 8 cutting edges you have to wear through.In addition, you could use most any spoilboard bit as a slot cutter if you mount it in a router table with a fence, but the ability to install any of three included bearing sizes lets you choose your depth of cut without having to use the router table or a removable fence on the handheld. I love using these when I want to edge-join two pieces with a spline, either loose for alignment or glued for strength.Finally, the 1/2" to 1/4" collet adapter is a nice bonus also. The set includes a spare bit retainer screw, the necessary Torx wrench for that, and the hex wrench for the bearing guides.I'm very happy with this set and will continue finding many uses for it far beyond simply flattening my CNC spoilboard.