Stamped from 18 gauge steel. Triple-chrome plated. High quality finish. Great looks. Works with all 5.152 inch carburetors. Base knock-outs for use with crankcase ventilation. Product Features:Stamped From 18-Gauge SteelTriple-Chrome PlatedHigh-Quality FinishGreat LooksWorks With All 5.125 in. CarbsBase Knock-Outs For Use w/Crankcase Ventilation