Each granule encapsulated by liquid magneisum chloride for fast action. Corrosion inhibitor added for metal protection. Safe on concrete older than 1 year and vegetation when used as directed. Effective to 0F Packed 50-50# bags per pallet. This product does not qualify for free shipping. Orders in Michigan will be delivered on our trucks for a nominal charge. Order outside Michigan will be shipped via common carrier and freight charges will apply. We will call you with a freight quote at shipping time.