Image Item No. Description  3001special  Brick 2 x 4 special (special bricks, test bricks and/or prototypes) Catalog: Parts: Brick  3001special  Brick 2 x 4 special (special bricks, test bricks and/or prototypes) Catalog: Parts: Brick  3001special  Brick 2 x 4 special (special bricks, test bricks and/or prototypes) Catalog: Parts: Brick  3001special  Brick 2 x 4 special (special bricks, test bricks and/or prototypes) Catalog: Parts: Brick