Neptunes Harvest 12 lbs Orange Label Pail Crab Shell Fertilizer - Pack of 4 Put around plants, Crab Shell will keep Slugs and snails off.FeaturesOrange LabelCrab Shell PailSpecificationsCapacity: 12 lbs Neptunes Harvest Organic Crab Shell is an excellent dry organic source of nutrients, including Calcium and Magnesium. It retains moisture in the soil and builds the organic matter. It also helps choke out weeds and keep moles, voles & mice from digging up bulbs and root vegetables.