Mr. McGroovy's Box Rivets make it easy for kids to build large and small cardboard creations. Just punch a hole in the 2 pieces of cardboard you want to connect, place rivets into the hole and snap them together. Create houses, forts, ships, sets for plays, front yard displays for the holidays. Great project for birthday parties, scout meetings, family projects and learning about engineering. A must have for school Makerspaces and Hacker Spaces. Students learn about engineering while making something on their own.