The power bracket is the standard mount: https://www.axiomaudio.com/power-bracket

There's also wall and ceiling mounts that'll work which I can no longer find on the site (and links to it from the speaker pages give a 404 error); so if you have a need for a non-flush mount I'd call Axiom and ask about these:
https://www.axiomaudio.com/full-metal-bracket
https://www.axiomaudio.com/full-metal-ceiling-bracket