The Kleinn Model DD-1 Direct Drive conversion kit is a smart, space-saving solution engineered for drivers who want to replace a weak factory horn without the cost or footprint of a full onboard air tank and compressor system. By eliminating the need for a separate air storage tank, the DD-1 utilizes a small, high-output direct drive pump that hooks up directly to your factory or aftermarket horn switch to deliver instant, loud, and reliable blasts the second you press the button.