Switch Box Mercury Mariner | CDI 114-7452A 3 CDI Electronics Mercury Mariner Switch Box | 114-7452A 3 High performance replacement ignition pack for various 18 HP, 20 HP, & 25 HP Mercury/Mariner 2 cylinder outboard engines. CDI Electronics outboard ignition pack Fits Mercury 18 HP 2 cylinder engines using the connection type pack from 1980 to 1987 with serial number range 5837437-0B238463 Fits Mercury 20 HP 2 cylinder engines using the stud connection pack from 1979 to 1987 with serial number range 5837437-B238463 Fits Mercury 25 HP engines using the stud connection pack from 1979 to 1987 with serial number range 5705532-0B238463 CDI determines the most common causes of component failure and designs their replacements to be better than the original Replaces Mercury 332-7452A 2 and 332-7452A 3 Replaces Sierra 18-5776