In many fields of application it is necessary to give both optical and acoustical alarms. This mini hooter with warning light was designed just for such situations. Many applications also require two alarm stages. e.g.,- Stage 1, optical alarm signal, and Stage 2, optical and acoustic warning. Since it is possible to control the light and the hooter independently of each other, such alarm combinations could be realized with the HPL/HPLB. The housing is made of impact-resistant ABS and the cap of polycarbonate. Optical signalling of the HPL is provided by a 7 Watt/Ba 15d bulb and the HPLB with a Xenon tube.