This is the siren included with the VIPER. If you want the VIPER sound, this is the siren. It is included with the current VIPER models. Compared to the old 514LN siren, it is one size smaller. By cutting the loop wire (1) on the siren, you can change from 6 tones to a single tone. By cutting the loop wire (2) on the siren, you can change the siren sound.