These Pro Ignition wire separators from Mr. Gasket are designed for 8mm spark plug wires. They are constructed from high-temperature ABS plastic and are chrome plated for lasting beauty. These wire separators help engine performance by minimizing ignition crossfire. They also prolong spark plug wire life by holding wires away from hot engine components, giving them a neat and custom look. These kits include two 2-wire, 3-wire and 4-wire separators, and an Allen wrench.