Dog Rocks Grass Burn Preventative are rocks that work like a filter in your dog's water to eliminate minerals like nitrates and ammonia that get in your dog's system and come out in a concentrated form in urine which burns the grass. The better tasting water will encourage your dog to drink more too! What are Dog Rocks? Dog 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 source of water, while eliminating urine burn on grass this will result in the end of those nasty burnt yellow patches on your lawn. Without the impurities in the water, Dog Rocks actually help your dog fertilize your lawn! This is great for you, your dog & your lawn! Dog Rocks are a completely natural product sourced from a reputable quarry in Australia. Original Dog Rocks only comes in the recycled brown packaging with the green and white label and carries the registered trade mark “Dog Rocks “. Any other product on the market is not the original so please beware.