The Deka-Arc series of spark gaps is designed for heavy duty electrical transient protection. Their 40,000 ampere (8 x 20 usec waveshape) capability makes them suitable for many direct lightning stroke protection applications and for power line protection when used with appropriate series resistances. They may also be used in circuits where long life is desired under repetitive pulse conditions. Capacitance of these tubes is less than 10 pF and initial insulation resistance is greater than 1 x 10E9 ohms. Tubes are available in DC breakdown voltage ranges from 230 to 10,000 volts. Units normally stocked are as follows, other voltages available on request.