PREMIUM MATERIAl. 5.5MM(OUTER DIAMETER)X2.1MM(INNER DIAMETER). Dericam 12V extension cable is made of pure copper material, featuring lower resistivity and better electrical conductivity. Flexible connectors resist breakage for superior durability. HIGH QUALITY. Copper wire AWG,22. The cable is made of pure copper material. Two or more 20ft(6 meters) extension cables can be cascaded together to meet the needs of 40ft(12 meters) or longer. MULTIFUNCTION. It is a DC male-to-female power cord. 5.5mm(outer diameter)x2.1mm(inner diameter) connector for power plug, 2.1mm center positive power connection type. PLEASE CHECK THE POWER PLUG SIZE BEFORE PURCHASE, DOES NOT WORK WITH OTHER CONNECTOR SIZE. STRONG COMPATIBILITY. Fits for any applications, devices and power adapters that require DC 12V power. Recommended cable for Dericam S1/S2/B2 WiFi IP camera, Amcrest, Foscam, SV3C, ZOSI, Annke, Reolink, Night owl, Swann, Lorex security camera. Or LED Strip, Router, printer, monitors, sensors, DVR, external hard drives, audio mixing and recording equipment etc. EASY INSTALLATION. Plug and Play, Easy to Use. With DC jack input and output, when your home surveillance system comes with short power cables.