Balsa wood or basswood strips, individual bottles of colored Pitsco Structures Glue, The Pitsco Bridge Book, student guide sheets – all the materials you need to complete an exciting bridge design and building activity. Packs are available for a class of 10 or a class of 25. Balsa wood strips are 1/8" x 1/8" x 24". Basswood strips are 3/32" x 3/32" x 24". Construction requires hobby knife or Timber Cutter, small clips, foam board, pins, and waxed paper, sold separately.