The LiftMaster LMH24R Red Horn is an indoor, two-wire audible warning device designed for use with LiftMaster gate operators, commercial door operators, and access control systems that provide a 12/24 VDC accessory output. It delivers a clear audible alert to warn pedestrians and vehicles when an operator is about to move or when a system alarm is triggered, making it a practical replacement part or upgrade for safety-focused residential and commercial applications such as warehouses, loading docks, parking structures, and industrial facilities. Its red finish enhances visibility in indoor environments, and the simple two-conductor hookup streamlines installation.
Operating on 12 or 24 VDC power, the LMH24R connects directly to compatible operator alarm or pre-warning terminals, with no programming required on the horn itself. For best results, mount the unit in a dry, indoor location where the sound can be heard clearly, and power it from a properly fused, supervised circuit as recommended by the operator manufacturer. Integrators and technicians typically configure the host operator to trigger pre-move or alarm outputs according to local codes and site safety policies. This LiftMaster accessory supports a wide range of operator brands that offer 12/24 VDC signaling, making it a reliable choice for installers seeking a straightforward, 2-wire indoor horn solution.