SA2 Series Gas Discharge Tubes Bourns SA2 Series High Voltage Gas Discharge Tube devices are designed for high isolation applications. The SA2 series features quick response time, long service life, a wide temperature range and is offered with a DC breakdowns from 2.4kV to 7.2kV. Bourns SA2 Series High Voltage GDTs are ideal for street lighting, medical devices, air conditioning, power supplies, projectors and welders.