LITKO flight bases are accurately laser-cut from 3mm clear acrylic. Each base features a cut peg hole with an engraved ring marking the upside of the base. The pegs will friction fit into the peg holes, but we suggest gluing them as well. We recommend our Craftics #33 acrylic glue for all our acrylic plastic products. To assemble, simply force the peg into the peg cutout on the base, it is designed to friction fit, but sometimes it may fit a little loose or tight than intended, be sure to test the connection before gluing.