These are awesome and easy to install. It does take a little elbow grease but thats okay. If you cant get the end grip of the boom off, just use a blow dryer and warm it up then twist and pull. It pops off and I slid the weight on and put the grip back on. Easy peasy. I plan on buying a few more because they are nicely made, heavy and lock surprisingly well.

This will not fit a boom arm with a 3/8" thread because the counterweight is not threaded. It will slide onto the shaft of a boom arm only if an end fitting is removable.

K&M describes this as "fits any K&M one-piece boom arm with 3/8-inch thread or 0.591-inch tube diameter" and this is incorrect. It is impossible to use on my K&M 21431 Mini Microphone Boom Arm because the threaded steel end fittings are permanently crimped into place.

On the plus side if your boom arm happens to - quality is great as you'd expect from K&M

This counterweight does not fit over the plastic end cap of the boom. You have to remove the end cap (not easy). And then the counterweight is too small to fit in the same place as the end cap. You have to move it towards the center (which limits the amount of balancing you can do). Now the end of the boom is ugly, and you'll want to replace the end cap and now your solution is fairly permanent (unless the cap now comes off easier).

I'm using a Roswell Mini K87 condenser microphone with a K&M 210/9 Telescoping Boom Microphone Stand. When the mic is extended on the boom arm for recordings and Zoom meetings, it sometimes lowers all by itself. Tightening the arm adjustment knob all the ay doesn't seem to alleviate the problem. With Brett Moore's assistance, I tried this K&M counter weight. Once attached to the boom arm, it provides a goodr balance for this microphone. The hollow plastic handle that is tightly fitted on the end of the boom arm must be slid off to install the counter weight. Using a hair dryer for 30 seconds to warm up the plastic handle permits you to easily slide it off the arm to install the weight. Warming the plastic part again makes it easy to slide it back on the end of the arm. This information from Brett was very important since K&M doesn't provide any instructions to install the weight. Its a one minute process to install the counter weight. Now the mic stays exactly where I want it without multiple adjustments. The fit and finish of the weight is what you would expect from K&M. It beats a sand bag or other home made attempt at steadying an expensive microphone on a stand. Set it and forget it.

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