thanks for the quick response FB ; I originally naively thought that Innovations made their cartridges or established unique specs for cartridges that were supplied to them for their inflaters ; your first sentence tells it all and answers my question - it's business nowadays - if you have a company , it initially makes business sense to buy mass produced cartridges & let the consumer make do.

but I guess they lost enough sales for the bike application that they decided it made business sense to develop another inflater ; and they did , it's the "Elite" model !!

thanks again !!