This pack contains three MakerBot Build Plates for the Replicator Z18 to use as spares or replacement parts with your 3D Printer. The build platform on the Z18 has two parts: a flat, sturdy aluminum base, and removable plastic tops called build plates. The ability to switch out build plates allows you to immediately move on to your next print, while setting aside your most recent print for careful removal later on. Build plates can also warp over time, especially when removing larger prints. The build plates are made from ABS plastic, and are designed to be covered with build plate tape before printing.