I’m a little late to this thread, but I use Tulster mag holders a lot. They can be easily switched from IWB to OWB, and work for multiple double stack mags by adjusting the tension device with the supplied Allen wrench. They are also available in single stack. I have two of each and they are fantastic. They work with CZ, Sig, and even Glock mags, thanks to the tension adjustment.

https://tulster.com/universal-...arrier-echo-carrier/