The 210pcs heat shrink cable terminal kit includes: Red 22-18 AWG---------90pcs cable cross-sectional area 0.5-1.5mm²; Blue 16-14 AWG---------90pcs cable cross-section 1.5-2.5mm² Yellow 12-10 AWG---------30pcs cable cross-section 4.0-6.0mm² Steps for usage: 1. Insert the two wires into the correct size connector. 2. Press the metal part with the pliers in the middle of the mating connector. 3. Heat both ends of the connector to secure the wires.