Material We Offer! Rock:-Green Glauconite Road Base-Green Rock 2x4-Green Rock 3x5-White Limestone Road Base-Clean Limestone-White Rock 3x5-White Rock 2x4-Bull Rock Dirt:-60x40-Sandy Loam-Top Soil-Clay Culverts:The size of culverts we offer are: 8 inches to 48 inches in diameter with a maximum length of 30 feet.