The DSM2/X protocols are for Spektrum radios - so if you have a Spektrum transmitter you can use this, or a Devo that's been flashed to be compatible. If you have any other transmitter it won't work, as far as I know.

BTW, if you want something that's quite tiny but still plugs in as normal, LemonRx might be a good bet. They have all the normal pins to plug in servo cables but without a plastic shell, so they're less bulky/heavy. Probably twice the weight of the OrangeRx one, especially when you factor in that you won't need the connectors on the servo leads, but it may be a suitable halfway house that saves a bit of mass and volume but keeps everything plug and play.