Basically a cheap-ish USB based cart/ROM reader with connectors on it for SNES and Genesis gamepads. Allows you to use the real games with an emulator, or back up your existing carts.
Apparently there are some issues with SA-1 games on it, but he's looking into something. I posted a mention that maybe he could speak to our devs here for more info on how getting the SA-1 working in the emulator was done that might help with getting those types of games running via that device properly.
Appears in the future it's work for other types of carts as well. A really nifty device I must say.