Wolo (BA-97) Pro-Tec Heavy-Duty Back-Up Alarm Designed for heavy-duty use Automatically adjusts to a voltage range of 12-24 volt vehicles The state-of-the-art electronics are sealed in rock hard epoxy for all weather usage The black plastic case is waterproof and has strong mounting brackets Produces a powerful beeping sound that is 97 decibels, to help warn when the vehicle is backing-up