The xl's won't work but most standard megas will. Clear megas won't
I'll try and get the exact ID on the tube part on Moday. Some carts may appear to not fit because of the little ridge where the conector pushes into the carto, but you can work past that usually and get them in.
The reason that they're considered disposable is that they are sealed plastic and while it may be possible to get them apart to replace the horn switch, it usually breaks the plastic. The main idea behind these was a short stealth
mod that I could use at my sons soccer games but the more I worked on it and the more it took shape and the price, it makes them cheap enough to not bother fixing..
Even as cheap as they are price wise, and despite the limitations on cartos or atties, they're still great quality and made very nicely.
hoog