SE Gas Discharge Tubes Littelfuse SE Gas Discharge Tubes (GDTs) offer high surge ratings in a miniature PCB surface mountable package that measures only 3.2mm x 1.6mm x 1.6mm. The low insertion loss of the SE series makes it ideal for broadband equipment applications. The capacitance does not vary with voltage, and will not cause operational problems with ADSL2+, where capacitance variation across Tip and Ring is undesirable. These devices are extremely robust and are able to divert a 500A to 600A pulse in a miniature package 1206 without destruction.