Whelen ALPHASL 200 Watt Remote Siren Scan-Lock feature allows you to toggle through 15 siren tones. Operates one or two 100 Watt siren speakers. Compact design is perfect for undercover and volunteer applications. Control siren tone through horn ring or separate switches. Hands-Free operation lets you cycle through two or three siren tones using horn or auxiliary control. Meets Class A requirements with most 100 watt speakers. Harmonically rich composite Air Horn tones. Output open/short circuit protection. Will operate from customer supplied switching controls. Pre-wired with one 16 pin quick disconnect plug for easy service and fast replacement. Easy to install. This is the Siren Amp only. Switches must be purchased separately. 2 Year Warranty