Dog Rocks - 200gDog Rocks are a 100% Natural Australian product that will save your lawn from those nasty burn patches that your Dog's urine can cause. Dog Rocks filter out impurities from water such as tin, ammonia and nitrates. These impurities are usually passed out through urine, and when grass comes in contact with these elements it results in urine burn on grass, resulting in a dead, yellow patch on your lawn. Dog Rocks give your four legged friend a cleaner