This DB9 offers dataline surge suppression for DB9 serial ports of data terminal and data communications equipment, including PCs, printers, modems and more. User-configurable for use with male or female captive DB9 ports. Offers protection on all nine lines, plus D shell chassis. Convenient DB9 input and output connects directly to the protected port, obtaining a ground outlet from the computer chassis. Surge suppression is handled with balanced arrays of high-speed avalanche diodes that divert excess energies created by electrostatic discharges away from network interface connections. Network surge suppressors reduce blown interface cards, garbled transmissions, system lock-ups and hard equipment failure by safely shunting dataline surges to ground.