Gravel, NY #1a, round x 1/4" Top dressing for walkways, gardens and pet areas, Type 2 underdrain Gravel, NY #2, crushed x 1" Subbase for concrete sidewalks; drainage stone ... # 4a ballast x 1-1/2" Used as Railroad Ballast- slightly large drainage stone Limestone, 1" crusher run x dust 1" Use for unpaved driveways, walkways, etc.Web