Image Item No. Description  47117  Brick, Modified 2 x 2 with Channels and Top Peg Catalog: Parts: Brick, Modified  7049b  Brick, Modified 2 x 4 with Wheels Holder, Trans-Clear Bottom Catalog: Parts: Brick, Modified  47115  Brick, Modified 24 x 24 without 12 x 12 Quarter Circle, with Peg at each Corner Catalog: Parts: Brick, Modified