K&M 21326 Adapter f Speaker Stands

This is a very simple and cheap plastic adapter, but proved to be exactly what I needed for a job. I don't know if its me but I very often have ideas for a simple gadget or piece of equipment to make my job or system work better, but when I search the internet I can never find that one thing, or if I can its only available in America or costs far too much to justify buying it.
I have four American DJ 6 spot tri bars which are great but that have a top hat mount on them allowing me to only sit them on the top of a stand and not over the stand to adjust the height. The problem is the lighting stands I have are too small in diameter for these and when I sit them on top of the stand they spin round and do not lock off. They don't feel very safe.
I needed an adapter that would fit over the top of my lighting stands and increase the size of the stand to snugly fit the ADJ bars. This adapter is perfect. It is a very tight fit over the stand (I use the Stairville BLS-315 Pro Lighting Stand B) and once fitted is a hell of a job to get it back off, but because of this tightness the ADJ 6 spot tribar is firmy gripped and I can lock it off securely.
there are other lighting fixtures that have the 40mm internal diameter that would also work perfectly with this. It is cheap for what it does and conveniently small and light. I think after 30 or so uses the plastic may begin to weaken under the pressure of the turn knob, but for the price it is worth it.