The 2030-42T-SM-RPLF is a fast-acting 3-electrode miniature gas discharge tube designed for surge protection in high-voltage applications. It features an initial DC sparkover voltage of 420 V (typical at 100 V/s) with a minimum DC sparkover of 360 V throughout service life, and a maximum impulse sparkover of 850 V at 5 kV/µs. The device measures 5 mm in diameter and 7.3 mm in length, offering a compact form factor with stable breakdown characteristics and insulation resistance exceeding 10¹° O. Operating over a temperature range of -40°C to +90°C with glow voltage around 70 V and arc voltage approximately 10 V, this RoHS-compliant component is ideal for protecting RS485, telecommunications, industrial electronics, and avionics systems against transient overvoltages.