The Plant Pro-Tec Dog & Cat Repellent formula uses a special combination of garlic oil, citronella, lemon-grass and cinnamon, each proven to repel dog and cats, in its patented slow-release system.  These repellents will keep four-legged pests from making messes on lawns, shrubs and flowers.  The patented, long-lasting and easy-to-use delivery system  sets it apart from less effective spray-on repellents that begin to break down when they come in contact with the air, and require reapplication every two or three weeks, or more often if it rains.  And this slow release system will keep on working for 6 to 8 months or more, even if it rains.  Using the repellents is easy: you just break the seal to activate the unit, then clip it directly to a plant, attach it to a nearby fence or lay it on the ground. Includes 12 units.