Yakamoz 90 Degree Right Angle Attachment for Rotary Tools - Compatible with Dremel 4000, 3000, 8200 & 275 Grinders - Power Tool Accessory for Woodworking, Metal Polishing & DIY Projects

No instructions were provided. A little tricky to install on my Dremel 4000, here's what I did: On the 4000, unscrew & remove the cover over the collet & nut. Screw on the right angle adapter's cover and screw coupling where the original cover was removed. Remove the collet provided with the springy shaft of the right angle adapter (mine was shipped with a collet on the shaft that is not compatible with my 4000, not sure why, never used this new collet, it was actually upside down when shipped...). Insert the springy shaft into the original collet, round side into the Dremel. The springy shaft also has a square side, there is a transition about half way up the spring. The square side inserts into the right angle adapter. Here's the critical part: the square side of the drive shaft must completely bottom out into the adapter to prevent slipping/stripping. So I ended up adjusting and adjusting the length of the shaft sticking out of collet many times until I got the max amount of square spring sticking out, yet could still thread the screw coupler all the way onto the right angle adapter. Geez, I have no idea if that made any sense, but it took me a while to figure it out. Instructions would have been nice. I used it a few times afterward, and it worked fine.