Velda Pond Guard Heron & Cat Scarer helps protect your pond fish from cats and herons by means of glaring flashes of light and a penetrating sound of a bird of prey. Once installed on the edge of the pond this unique Pond Guard will trigger an immediate flight response that will stop cats and herons getting close to the pond and catching all your valuable fish. The concept of this pond guard is ingenious, yet simple. At an angle of 180° and within a radius of up to 25 metres (82 ft.), a movement sensor will detect an approaching heron or cat and immediately emit a number of glaring flashes and the penetrating sound of a bird of prey. Result: The heron or cat takes flight, not to return to this pond in a hurry.