The MakerBot Replicator+Tough PLA and Smart Extruder+ Bundle consists of 3 rolls of high-strength new Tough PLA in slate gray. It is as tough as ABS and as user-friendly as PLA. It is less brittle than PLA and more resistant to warping than ABS. The Tough PLA is compatible with MakerBot Replicator 5th Gen, MakerBot Replicator Z18 and MakerBot Replicator+. It comes bundled with the Smart Extruder+ for ease and convenience to the customer.