TSP's premium ignition wires are designed for superior performance and durability. A spiral-wound Kevlar? core suppresses RFI (radio-frequency interference) and features 500 ohm per foot resistance for excellent performance. Around the core is a fiberglass braid which provides superior pull strength. The outer jacket is composed of premium high-density silicone rated at 450? F and features a quality gloss finish to resist damage from water and chemicals. This set is pre-cut and assembled for GM LS engines.