Image Item No. Description  2412b  Tile, Modified 1 x 2 Grille with Bottom Groove Catalog: Parts: Tile, Modified  6180  Tile, Modified 4 x 6 with Studs on Edges Catalog: Parts: Tile, Modified  6178  Tile, Modified 6 x 12 with Studs on Edges Catalog: Parts: Tile, Modified