Recommendation ITU-T K.pnj defines the basic electrical parameters to be met by silicon PN junction voltage clamping components used for the protection of telecommunications equipment or lines from surges. Examples of equipment include those located either within a telecommunication centre [b-ITU-T K.20], customer premises [b-ITU-T K.21], in access or in trunk networks [b-ITU-T K.45]. It is intended that this Recommendation be used for the harmonization of existing or future specifications issued by PN diode surge protective component manufacturers, telecommunication equipment manufacturers, administrations or network operators.