The EZ-Flash 3in1 Expansion pack is a multifunction Slot 2 device which will add further functionality to your DS and CycloDS. Although originally designed for the EZFlash V slot 1, a Japanese coder named Rudolph has contributed some excellent software which will allow you to use all the features with a CycloDS. In one device, it can add rumble support, a RAM expansion, GameBoy Advance ROM support; and will also allow you to back up your retail DS cartridges to your Cyclo.
It comes in two formats, one that looks like an original GBA cartridge; and one in the shape of the DS Lite GBA slot cover. That means all this extra functionality for DS Lite owners without a cart sticking out