This is dremels new quick change mandrel for their rotary bits. I have one and it works great, you can change cutters in 3 seconds, the problem is there are too few options to accomodate this new mandrel. There are plenty of old style 1/8" shank bits/cutters/burs ect.. but none are interchangable with this one. They have diamond cutters, carbide cutters and aluminum oxide cut-off disks for this mandrel but thats about all. I see no way to manufacture heads for say a router bit or grinding bur. Just my opinion.