EZ-Oil Drain Valve, Large Body, Locking Lever, 1"-12 NPT Thread Size, Fits Listed Caterpillar Engines With Optional Tapered NPT 1-12 plug (1-1/4" diameter) - 3304, 3306, 3406, 3406B, 3406C, 3406E, 3408, 3412, 3456, 3176, 3126, C-10, C-11, C-12, C-13, C-15 (Acert models use valve # EZ-215), C-16, C-18