This wire separator is designed for 8mm spark plug wires to help minimize ignition crossfire and improve engine performance. It is constructed from high-temperature ABS plastic and is chrome-plated. It also prolongs spark plug wire life by holding wires away from the hot engine and moving components, giving them a neat and custom look. This kit includes two 2-wire, 3-wire, and 4-wire separators, and an Allen wrench.