Are you frustrated that your perfect lawn has blemishes after your dog urinates on it? With these safe Dog Rocks stones for dog urine stains on the lawn, you no longer have to worry. All you need to do is place a pack of stones in a water bowl of about 2 liters. These stones absorb excess nitrates and other trace elements from the water before your dog drinks it. And with less nitrates going in, there are fewer nitrates coming out! This means less nitrates in your dog's urine, which ultimately means that his pee won't kill the grass. The stones last for two months and become less effective after that time. Therefore, replace the stones every two months to ensure their effectiveness. Most importantly, this anti-urine solution does not alter the pH level of the urine and has no side effects for your four-legged friends, and it is even safe for your cat! Material: Rock | Weight: 200 g (2 or 3 stones) | Perfect prevention and treatment of burn spots on grass caused by your dog's urine | One pack per water bowl can last two months (comes with a reminder sticker) | No change in the pH balance of your pet's urine | No harmful effects on dogs, and safe for cats as well.