AT Pro / AT Gold / AT Max control box mounting plate
This is either for repair if you have stripped or damaged the original 2 screw controller mounting or an addon to reinforce the existing controller mounting system to prevent it from occurring in the first place.
It uses the four existing speaker cover screws to hold it in place and is fitted directionally with the word TOP on the saddle mount at the top.
Just remove the four screws holding the speaker mount in place and add the saddle mount and replace the 4 screws.
DO NOT over tighten the screws, just nip up securely.