Signal devices, namely, acoustic, optical and radio signal generators, electric warning lights, electric winking warning lights and flashlights, electric warning signal pillars, buzzers and horns, included in this class, namely,electric buzzers and electronic warning horns; sirens, bells, included in this class, namely, signal bells, radio elements as an accessory for signal devices for signaling, warning, protectional purposes and guidance, namely, radio receivers and transmitters