Video cable refers to the cable that transmits video signal (VIDEO), which can be used for signal transmission of monitoring system. General model: SYV75-X (X represents its insulation outer diameter 3mm/5mm, the larger the number, the thicker the wire diameter) In SYV, S---coaxial radio frequency cable, Y---polyethylene, V---polychlorine Vinyl. 75 represents the characteristic impedance, the video line is divided into 75-3 (100 meters), the transmission distance that can work normally is 75-5 (300 meters), the transmission distance that can work normally is 75-7 (500-800 meters) The transmission that can work normally Distance 75-9 (1000-1500 meters) The transmission distance that can work normally is generally SYV75-5. The same manufacturer may also provide products at different price points. The specific difference is whether the copper used is pure copper or copper-clad aluminum. , or the number of twists of the copper core of the outer shielding layer, such as: 96 braid (referring to braiding by 96 fine copper cores), 128 braid, etc. The more the number of braids, the better the shielding performance, so this needs to be paid attention to when purchasing products. .