Image Item No. Description  32531  Technic, Brick 4 x 6 Open Center Catalog: Parts: Technic, Brick  32555  Technic, Brick 5 x 5 Right Angle (1 x 4 - 1 x 4) Catalog: Parts: Technic, Brick  32532  Technic, Brick 6 x 8 Open Center Catalog: Parts: Technic, Brick