1. Tone charactor: Siren, manual, wail, yelp, hi-lo, horn, radio. 2. Handhold mike, with controller. 3.Monolithic integrated 1. It conform to national standard GB8108-1999. 2. Tone charactor: Aux, yelp, wail-1, wail-2, warn and yelp/8s, lamp-a-b-c-d and dual-tone and so on. 3. Handhold mike. With controller. 4. Monolithic integrated circuit in steadier performance. 5. With two light controllers.