Bosch loudspeaker has excellent quality, performance and innovative combination in the field of public broadcasting. These loudspeakers are the rich experience crystallization of Bosch in professional audio field for more than half a century, can meet almost all the requirements of sound amplification system. Basic function embedded ceiling speaker is suitable for general application. The function perfect speaker with high sound pressure level and wide frequency range, suitable for the warehouse, school, office, gym, hotel and restaurant provide clear voice and music in the radio. The speaker assembly consists of a 6 W speaker and frame with a 100 V matching transformer on the back. The front is fitted with a round metal mask. The refined appearance and natural white coating make the speakers perfect for any indoor situation. In addition, it is equipped with a dust cover to protect the rear. 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. Security in accordance with EN 60065 standard anti-collision conform to DIN VDE standard 0710 - part 13 regional certification European CE installation/configuration speaker components can be installed easily and quickly on the ceiling of the hole, and two built-in spring loaded locking clip in ceiling fixed (applicable to the thickness of the ceiling and wall panel for 9 to 25 mm). The circular template attached to the speaker is used to mark the mounting hole with a diameter of 172 mm (6.7 inches). The junction box loudspeaker is equipped with a two - way terminal box with push - in connector. The three jumper joints on the matching transformer are used to select rated full power, half power, or quarter power (increment 3 dB). The l30bc 80/01 flameproof cover in case of fire, flame or smoke will spread throughout the building through the ceiling mounting hole. LBC 3080/01 steel flameproof cover can be installed on the loudspeaker to prevent the flame from penetrating the mounting hole through the ceiling speaker. It is mounted on the speaker assembly using four self-tapping screws attached to the flameproof cover. The flameproof cover is provided with a hole for installing two gaskets (with them) and two cable sealing plugs (PG 13).