200 Grams, Dog Rocks, Work By Simply Placing Contents Of Dog Rocks Packet Into Pet's Water Bowl & Filling It With No More Than 2 Litres Of Water, Lawns Will Start To Look Greener & Fresher, Holds Special Properties That Helps Pet FertilizeLawn, Not Destroy It, Laboratory Tested & Are Safe For Pets, Increase The Properties Of Boron, Barium, Manganese & Strontium While Decreasing Tin Levels In The Water.