Better capacity for resisting disturbance, good transmission quality, energy saving, high reliability and cost saving, best choice for short line equipment, no power required. Simply and professional power cabling. Easier installation, save time and more securer cable connection. No soldering, no splicing, no crimping is needed to use and install. Only a small screw driver needed, you simply screw your cable and just plug it in. Internal Diameter: 2.1mm, External Diameter: 5.5mm. Application: Work for CCTV security camera DVR and LED strip light. Product description Specifications: Material: Zinc Alloy + Plastic Size: 6.2 X 1.4 X 1.2cm (L*W*H) Internal Diameter: 2.1mm External Diameter: 5.5mm Colors: Silver + Green + Black Package Included: DC Power Connector X 12 Pairs Note: Using current not exceed 2amps for appropriate.