Features: Using brass cores, with high load capacity, good conductivity, low resistivity, and stable wiring. The insulating sleeves are make of nylons, antioxidation, matching crimp Terminals, safe to use. Just crimp or solder to your wire and cover with insulating sleeves for a clean, solid, and professional connection. The male and female docking terminals are easy to install. No complex are required, and the connection can be completed in just a few step. Suitable for the connection in power cable with electrical equipments. Specifications: Materials: Brass and Plastic Size: As Shown in the Picture Package Includes: 50PCS Golden Female 3.9mm 50PCS Golden Male 3.9mm 50PCS Silver Female 3.9mm 50PCS Silver Male 3.9mm 100PCS Long Insulating Sleeve 100PCS Short Insulating Sleeve note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.