High-Temp Fiberglass Heat Sleeve for Spark Plug Wires – 5FT x 1/4″ Protection Size: 5FT x 1/4" (6MM). High-Temp Fiberglass Heat Sleeve for Spark Plug Wires. Don't let heat destroy your spark plug wires. Choose our High-Temp Fiberglass Heat Sleeve for unparalleled protection and performance. byJuly 3, 2026