Tetrix Prime Quick Rivet Connectors should be used in conjunction with Quick Rivet Pegs (sold separately). The use of the Quick Rivets and Pegs allows you rapid assemble and disassemble structures – enabling you to try many different designs in a snap. This is a huge plus for classrooms with minimal time and storage. Plus, this connector also accepts the LEGO Connector Peg, so it's simple to attach LEGO components to a PRIME robot. Made of ABS plastic.