Cat & bird repellent devices - Simply screw on a fence or stick them to a wall to protect your house | Anti-climb spikes – effective deterrent spikes to guard against intruders without causing harm. | Install anywhere – cat repellent outdoor plastic strips - install on top of any flat surface! | Snap to fit – bird spikes kit splits every 4 inches to fit on all lengths of fence & boundary. | Great value 12 pack – 12 individual 1 foot (30 centimeters) cat deterrent spikes covers 3.7 meters