Product material: nickel-plated outer layer, not easy to oxidize, made of high-quality metal, rubber and plastic, corrosion-resistant, fast and stable transmission and long service life. | Specification: 5.5x2.1mm/0.22 * 0.08 inch. | Design features: each connector is equipped with a waterproof cap, which makes the plug windproof and waterproof and improves the safety of wires. | Application: widely used in car audio, video communication, tape recorder, stereo, telephone, etc. | The package includes: DC-099 power mother panel mounting connector * 7; 5.5x2.1mm barrel connector * 7; Dust cover and gasket * 7 sets.