The 2039-80-BLF is a precision, fast-responding high-voltage gas discharge tube (GDT) surge protector designed for board-level protection of high-bandwidth applications such as xDSL, cable broadband, and high-speed Ethernet. This miniature device features a 5 mm diameter through-hole or cassette mount configuration with a DC sparkover voltage of 800 V (±20% @ 100 V/s) and impulse sparkover of 1250 V @ 1000 V/µs, providing rapid response to transient disturbances. The 2039-80-BLF offers exceptional energy-handling capability with a maximum single discharge rating of 5 kA, low capacitance of less than 1 pF, and high insulation resistance exceeding 10? O, while maintaining stable long-term performance across an operating temperature range of -55°C to +85°C. Its RoHS-compliant design and compact form factor make it ideal for protecting sensitive electronic circuits from surge damage while minimizing board space and insertion loss.