(75pcs Solder Seal Wire Connectors + 135pcs Heat Shrink Crimp Butt Connectors). HOW TO USE HEAT SHRINK CRIMP BUTT CONNECTORS?. (3) Twist and insert into splice barrel in the middle. PREMIUM COPPER CORE AND HEAT SHRINK TUBE: Made of high quality tinned copper and adhesive lined heat shrink tubing. Leia Mais