The Mitsubishi L300 allready donated a horn to one of its L400 siblings. Tine to upgrade. The Hella Supertone horn kit is almost a direct drop-in replacement for the stock horns. You only need to change the odd Mitsubishi connectors for ordinary female spade connectors. I would estimate these horns are about 30% louder than stock. They are rated 118dB and 66 watts each.