I bought these most interesting square FAL drivers awhile back for a project that never moved;
They are 5.5 inches X 8 (total outside diameter)
They are 3.5 X 6.5 (total membrane diameter)
They have huge magnets, and are basically new, I've not used them but the fellow that I bought them from must have had them mounted. I can provide pictures if you text me @ 250-317-7888.
Asking $450 USD
Don