Daystar, Universal Firewall Boot, Single, Accommodates 3/8" to 1" Diameter Wire Bundles, fits any vehicle that needs a wire loom, KU20040BK, Made in America , Black Safely and cleanly run wires through firewalls and bulkheads Protects wires from sharp edges; prevents wire chaffing and shorts Eliminates air/water leaks Fits a variety of wire thicknesses and bundles from 3/8 inch to 1 inch; 1-1/4 inch hole required for installation Works great for tubing and air lines