Cheaper boom arms have a tubular base that mounts into a desk clamp. There also exist flanges that can accommodate this same tube base. A project I’m working on needs three of such flanges.
I own one generic model of such a flange, so I know they exist. But the only models I’ve been able to find for sale on their own are branded and cost around $30.
https://www.bhphotovideo.com/c/product/534691-REG/K_M_23855_000_55_23855_Table_Flange.html
There is at least one ebay listing that comes with this flange for about $15.
I haven’t figured out the right search terms to track these down. Does anyone know of a source for these cheaper generic flanges?