DescriptionDiy crafts 42\ rotary grinder tool flexible flex shaft fits dremel this is a 42 grinder attachment which fits the majority of rotary tools. Connection is for head with 3/4\ (19.05mm) thread. Work with the dremel 100, 200, 300, 3000, 4000, 7300, 7700; foredom, toolshop, performax, milwaukee m12, etc. If you're a diy-er, hobbyist or craft worker turn your rotary tool into a grinder with this flexible shaft attachment. Rotary tools are incredibly versatile and this accessory gives you even more functions. Plus, the flexi rubber non-slip shaft lets you take really control over the job in hand. Shaft installation as shown in attached picture: 1) remove rotary tool collet nut, and rotary tool top cap. 2) slide collet nut onto shaft core. 3)insert shaft core into collet. 4) tighten collet nut. Make sure the shaft core is hold tightly in the tool. 5) screw shaft connector onto the rotary tool. This will ensure the shaft core push back into the shaft. Bit installation instruction: 1) insert the l bar included into the hole at the collet side of the shaft. 2) unscrew the shaft collet nut. 3)insert bit, not included, into the shaft collet 4)tighten shaft collet nut. 5) remove the l bar