These steel rotating spikes are the perfect deterant to keep away intruders. They can be mounted on a 20mm bar and attached to the top of any wall or fence with brackets ( can also be supplied ) . The steel fencing spikes sit proud acting as a visual deterant but if an attempt is made to scale them then they will rotate 360 degrees around a bar. Dimensions : Square Colar : 150mm X 50mm X 50mm Square Box Section Corrigated Pales : 70mm X 155mm Overal height is : 340mm