Biral Thunderstorm Detectors are self-contained standalone devices that detect the presence of all forms of lightning including intra-cloud, cloud to cloud and cloud to ground. BTD-200 Lightning Warning System The BTD-200 Lightning Warning System is a complete, out-of-the-box, self-contained sensor that reliably detects the presence of all… BTD-200 Lightning Works Messenger The BTD-200 Lightning Works Messenger allows email and SMS text messages to be sent automatically when thunderstorm activity… BTD-300 Thunderstorm Detector The BTD-300 Thunderstorm Detector is a standalone sensor that reliably detects the presence of all forms of lightning… BTD-350 Thunderstorm Detector The BTD-350 Thunderstorm Detector is a standalone sensor that reliably detects the presence of all forms of lightning…