220 PCS Solder Seal Wire Connectors and Heat Shrink Butt ConnectorsStep to Use Heat Shrink Butt Connectors:1. Insert the two wires to the right size connector.2. Crimp the metal part in the middle of the butt connector by pliers.3. Apply heat to the two end of the connector to make it tighten up the wire.Instructions for use Solder Seal Wire Connector:1.Insert the wires into the solder sleeve.2.Apply heat to the soldering while swinging the hot air gun mildly.3.Heat close at the highest setting (used a 1500w heat gun)until you see the solder shine then stop.Job done.4.Great wiring solution for hard to reach or limited space areas. Since no crimping is required for these solder wire connectors, you can easily use them in hard to reach or limited space environments. Simply position the stripped wires into the solder sleeve and apply heat to finish the connection. Make properly soldered and waterproof connections in less than 30 seconds.Package Included:145 PCS Heat Shrink Butt Connectors:10 x Yellow Heat Shrink Wire Connectors: Cable cross-section 0.2-0.35 mm (A.W.G.:26-24);50 x Red Heat Shrink Wire Connectors: Cable cross-section 0.5-1.0 mm (A.W.G.:22-18);50 x Blue Heat Shrink Wire Connectors: Cable cross-section 1.5-2.5 mm (A.W.G.:16-14);15 x Black Heat Shrink Wire Connectors: Cable cross-section 2.5-4.0 mm (A.W.G.:14-12);20 x Yellow Heat Shrink Wire Connectors: Cable cross-section 4.0-6.0 mm (A.W.G.:12-10);75 PCS Solder Seal Wire Connector:10 x White Connectors: Cable cross-section 0.25-0.34 mm (A.W.G.:26-24)30 x Red Connectors: Cable cross-section 0.5-1.5 mm (A.W.G.:22-18)30 x Blue Connectors: Cable cross-section 1.5-2.5 mm (A.W.G.:16-14)5 x Yellow Connectors: Cable cross-section 4.0-6.0 mm (A.W.G.:12-10)