These interlocking pond protector rings are designed to cover your garden pond protecting your fish from predators such as cats and herons. They are virtually invisible from just a few metres away, your pond is protected without spoiling the aesthetic of your garden. The protector rings simply sit on top of the water and create a protective layer without any gaps as they fully interlock .This pack contains 20 hexagonal discs and 40 clips which covers approximately 1.6 sqm .The rings can be connected together (via the clips provided) to fit most shaped ponds forming an impenetrable protective layer. If fitting this product to deter Herons it is suggested to place the rings 2 deep from the edges of the pond (as herons fish from the edge).