FWIW, my 2XL Schuberth C3Pro fit in the top case, albeit on its side. I have the Sena 10U so the Bluetooth is internal, but the helmet fit. Also able to fit my 3XL Olympia Moab jacket as well, at the same time - and a pair of Held Wet-and-Dry XL gauntlet gloves. I can't see fitting two helmets in there, but it will hold everything I normally put in my Shad SH50 top case, so that's good.