Image Item No. Description By  3700  Technic, Brick 1 x 2 with Hole Catalog: Parts: Technic, Brick 1  3701  Technic, Brick 1 x 4 with Holes Catalog: Parts: Technic, Brick 1  3709c  Technic, Brick 2 x 4 with Holes on All Sides - Solid Studs Catalog: Parts: Technic, Brick 1