1.Features Benefits Extremely high EMI/RFI suppression along with a very low resistance to help deliver the most spark possible. Conductor style: spiral core,distributor boot material: silicone, heavy duty 8.0mm diameter silicone jacket to protect the Kevlar spiral wound core from heat, moisture and chemicals. 2. These sturdy spark plug wires are durable and guaranteed to withstand wear and tear. The high temperature silicone boots provide excellent heat and oil resistance, while the stainless steel and brass terminals provide excellent conductivity to maximize performance. 3.Fit for Small Block Chevy Fits HEI (High Electronic Ignition) systems with Chevy small block engines including 262 265 283 302 305 307 327 350 383 400. 4.Notice It has 9wire set that includes nine plug wires and one coil wire. This high performance racing spark plug wire set has black 90 degree boot for HEI distributor.