The BTD-300 is a single site, standalone thunderstorm warning system capable of locating all forms of lightning up to 83 km (51 miles) away, without the need for a mobile or internet connection, and requires no ongoing data subscription costs. Designed and manufactured by UK-based company Biral in 2012, the sensor uses a unique quasi-electrostatic technique exploiting lightning signals between 1-50 Hz, which greatly reduces false alarms by operating below all forms of radio interference. This electrostatic technique also provides exceptional sensitivity, detecting >95% of all lightning flashes within 60 km. Furthermore, the BTD-300 warns of potential overhead lightning activity before the first lightning strike is generated by the thunderstorm, by continually monitoring changes in the atmospheric electric field. The sensor is low power and maintenance and is designed for continuous operation in harsh weather conditions.