Distributor Cap for Inboard Engines OEM E64-0007 Sierra Replacement 18-5243. Regitar USA replacement distributor cap designed for inboard/marine engines including Mercruiser late model V-6 applications. Twist-on closure, modern style, USA-made small business brand. Item weight approx. 11.7 ounces. Package dimensions ~7 x 5 x 4 inches. Fits Mercruiser Late Model V-6 (4.3L Alpha/Bravo) and compatible applications where OEM E64-0007 / Sierra 18-5243 is specified. Supports straightforward installation and reliable ignition performance in marine environments.