V3 Sound Bluetooth Receiver

V3 Sound Expanders have a huge selection of sampled instrument voices (the Accordion XXL version has 928). To use it effectively one needs a MIDI interface capable of changing bank (group) designations and entering the individual instrument code - plus the instruction manual with all the numbers in...The USB receiver gives access to an App written for iOS and Android, which logs all the instruments, within their individual banks and permits various permutations. Very sophisticated. The only thing that baffles me is that the V3 is tiny and incompatible with rack mounting. It is practically begging to be used as a backpack device - but V3 don't market a battery pack!