A great system for emulation of 3DS, DS and honestly most systems.

More powerful that the Retroid Pocket Duo, powerful enough to handle many steam games as well as emulation of 3ds, switch and other systems.

If you're going to do emulation on a handheld like the Retroid devices, a MicroSD card is important. Several options exist depending on the collection, newer systems obviously require larger SD cards and older systems can do with smaller cards.