The 2031-42T-SMLF is a miniature 2-pole gas discharge tube designed for fast-acting surge protection in telecommunications, industrial electronics, and avionics applications. It features an initial DC sparkover voltage of 420 V at 100 V/s, with a minimum DC sparkover of 360 V throughout service life and a maximum impulse sparkover of 850 V (5 kV 1.2/50 µs). The device exhibits stable breakdown characteristics, a glow voltage of 70 V at 10 mA, and an arc voltage of 10 V at 0.1 A, with a glow-arc transition current of 0.5 A. Operating over a temperature range of -40°C to +90°C with an insulation resistance of 10? O, this RoHS-compliant component is ideal for protecting high-voltage communication ports such as RS485 and SDI interfaces when paired with TBU surge protection devices.