A rugged, smart and easy-to-use alarm transmitter designed for people exposed to threatening situations at work e.g. in prisons, psychiatric clinics, emergency wards, retail and industry. The small and lightweight Ascom a51 has two alarm buttons, one for attention and one for emergency. It offers a range of smart features for maximum user-friendliness and boasts a robust yet subtle design which is intended to emphasize the professionalism of the user. Pull-cord, man-down and no-movement alarms together with positioning via IR/LF and acoustic location signal guarantee high security for the user.