The BTC900N Gas Discharge Tube 1812 RoHS is a device manufactured by Bourne that consists of a gas-filled tube with two concentric electrodes. Its purpose is to protect sensitive electrical equipment from transient surges and overvoltage spikes. It can provide fast and efficient protection from both line-to-ground and line-to-line transients. This product is RoHS compliant, meaning that it contains no hazardous materials and is safe for use in electrical circuits. The GDT is housed in a black polyester case and is rated for a voltage of 900 volts with a maximum energy rating of 1500 watts. This product also has a typical response time of less than 1 nanosecond.