DOG ROCKS are a new and exciting product used to help prevent those nasty burn patches appearing on your lawn when your loving pet takes a pee. By simply placing contents of DOG ROCKS packet into your pet's water bowl and filling it with no more than 2 liters of water your lawns will start to look greener and fresher.DOG ROCKS hold special properties that help your loving pet fertilize your lawn, not destroy it. DOG ROCKS have been laboratory tested and are safe for your pets.For best results - DOG ROCKS need to be replaced every 2 months to ensure your pet does his job in helping look after your green grass.The weight of dog rocks varies from packet to packet. Average weight is 200gms.