MSD Shrink Sleeve, Spark Plug Wires - 3407MSD Shrink Sleeving can be used to protect connections throughout the vehicle as well as spark plug wires. Part Number: 3407 Simply install the Shrink Sleeving over the connection and apply heat. The sleeving will shrink tightly around the wire and protect it. MSD Shrink Sleeving will not split and is designed to withstand high underhood temperatures. Features and Benefits Also fits spark plug wires Shrink sleeving to protect connections