Ease of : the right size solder sleeve and insert the wire. Then twist the wires . Heat the entire heat shrink tube evenly for about 10 seconds until melted. Finish! Insulation: Heat shrink tubing shrinks and tightly wraps the wires after heating. Has good water resistance and strong insulation. It is the perfect replacement for soldering or insulating tape. Quality Solder: Solder enough around the wire, melt and , until a seal is formed on the wire. Make the connection lasts Hot melt adhesive keeps the wires from slipping out of the terminals. Wide application: 50 solder wire connectors of different sizes in one box can fully meet your needs, suitable for connecting wires of various sizes. Material: plastic colour: red+blue+yellow+white Package Contents: 50 x Wire Connectors Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.