Skylink SA-001S Wireless Outdoor Solar Siren Security Alarm Accessory for SkylinkNet, M-Series and SC Series Systems NO MONTHLY FEES and easy DIY (Do It Yourself) installation LOUD 110 DECIBEL SIREN TRIGGER THE OUTDOOR SIREN manually or automatically when the internal alarm system is activated LIFETIME SUPPORT - Toll free 1-800-304-1187, support@skylinkhome.com