These clamps are part of the EZ-Release Build Surface. A custom fit, clip on build surface made from flexible polycarbonate for your Makerbot Replicator 2/2x. Check out the video here to see how it works: https://www.youtube.com/watch?v=77-BSpBddb8 The flexible build surface mounts on top of your existing build platform and provides excellent adhesion and easy removal. You will need to download the clamps and print them out (2 of each is required). The installation instructions give you the recommended print orientation and settings for the clamps. Additional accessories that can be ordered along with the surface include: On Sale! Follow the order link below for details. Here is the order link if you're interested: https://docs.google.com/forms/d/1RQ5N6uHJ60KT98FfC-BVV9Isq9c-u-Vb76Z451QXv1A/viewform Happy printing!