2055-xx-SM Gas Discharge Tubes Gas Discharge Tubes (GDTs) are used to protect personnel and sensitive equipment from hazardous transient voltages. Bourns GDTs are used in primary and secondary applications and can withstand multiple applications of high surge current energy in excess of 25 KA. Bourns offers standard 8 mm GDTs and a 5 mm mini series GDT in two and three electrode versions featuring long service life and low capacitance and insertion loss. An optional, proprietary Switch-Grade Failshort is offered on the three electrode version to provide superior protection from thermal runaway. Bourns GDTs meet or exceed virtually all industry specifications regulating the use of Gas Discharge Tubes.