The Mobile Fab device is a plastic recycler that, using a series of pumps, tubes and wires, grinds No.5 plastic into a fine powder, which is fed into the 3D printer attached to the front of the bike. Passersby are invited to bring pieces of discarded polypropylene, the only plastic Fabraft can handle for the moment, to their bike. After a couple of hours, processing and printing the material, they’re rewarded with such items as a Fabraft medallion, to be inserted into the spokes of their own bicycles. Best of all, there’s no charge, just plastic.