A large grouping of lightweight modular steel tube-and-connector shelving designed by Poul Cadovius, 13mm series, manufactured by Abstracta Structures, Inc. circa 1968. Included are 133 steel rods, 81 steel connector joints, 24 textured plastic shelves, three wire shelves, a branded Abstracta disconnector tool for disassembly, and a 1968 catalog. The 24 plastic shelves include the following sizes: 23" x 31" (one), 23" x 23" (two), 10" x 31" (four), 16" x 16" (two), 23" x 10 1/2" (two), 13" x 10 1/4" (four), 10 1/2" x 10 1/2" (four), 10" x 4 3/4" (five). The steel rods range from 31 1/4" to 4 3/4" in length. Some rust or pitting to many of the steel rods. The shelves are in good condition, with a few spots and some mild scuffing from use.