Zoom ratio is the ratio of the maximum and minimum focal length of the zoom lens and the vari-focal lens. 

Zoom lens change the focal length without changing the position of the subject by moving a part of the optical system of the lens. 

Weather Proof Design, an IP66 rated weather proof housing, protects the camera from damage caused by rain, snow and dust and allows it to be used outdoors. 

Vandal Proof is designed to withstand rugged environments. Aluminum die-casting enclosure and Poly Carbonate clear dome enables stable 24hours security tasks.