The l30bc 94/15 is a strongly directional speaker designed to provide high quality voice and background music playback in indoor and outdoor applications such as shopping center, factory and sports ground. The basic function strong directional loudspeaker is suitable for applications where the direction of the beam needs to be specified. Its principle is similar to the principle of spot light, which aims to provide local sound reproduction effect. Typical examples include restaurants, exhibitions, factories and shopping centers. Strong directional speakers prevent liquids from splashing in and are therefore suitable for outdoor use, even in very humid environments. The speaker housing is made of high strength ABS flame retardant material (in accordance with UL 94 V0 standard). The case of the strong directional speaker is white-coated and comes with the same color steel mounting bracket. They fit on walls or ceilings. All Bosch speakers are certified to meet IEC 268-5 power handling capacity (PHC) standards and can operate continuously for 100 hours at rated power. Bosch has also conducted simulated acoustic feedback exposure tests to ensure they can withstand twice the rated power in a short period of time. This ensures high reliability of the speaker under extreme conditions, improves customer satisfaction, extends service life, and significantly reduces the probability of failure or performance degradation. All plastic parts are made of high strength ABS flame retardant material (in accordance with UL 94V0 standard). Like all Bosch products, they are carefully designed to ensure strict safety standards are met. These speakers meet all safety and installation requirements in the EN 60065 standard. Waterproof and dustproof in accordance with EN 60529 and IP 63 standard certification European CE installation/configuration all device attached color four core connecting cable, and each color of cable core even pick up to 100 V matching different primary tap transformer. This allows the user to select the rated full power, half power, or quarter power (increment)