Just twist the wire ends together, slide over the sleeve and heat it up with a hot air gun.
The solder will melt to join the copper strands, the two rings of glue will melt to seal around the cable insulation and the sleeve itself will shrink tightly around the wire for a strong, permanent, weatherproof joint.
10 x WHITE For wires up to 1.7mm dia.
20 x RED For wires up to 2.5mm dia.
12 x BLUE For wires up to 4.5mm dia.
5 x YELLOW For wires up to 5.5mm dia.
47 PIECE HEATSHRINK AND SOLDER JOINER PACK #HSSCPAK