All Sports Marking Lime is a calcium carbonate powder that is highly preferred by most ground keepers and coaches in America. It is specially formulated to produce a better marking material for any field or track event. This free-flowing pulverized limestone is beneficial in increasing soil pH levels and it creates guides for fields without harming the grass, soil, or vegetation. It is finely ground to help with the deep penetration of fertilizers. Proven to be safe for pets and children. Available in 50 lb. bag.