1.1 This part of ISO 8668 specifies the particular characteristics of a terminal junction system (TJS), designated as type 1 and intended for use at temperatures between − 55 °C and + 155 °C. 1.2 The junction systems covered by this part of ISO 8668 comprise: a) feedback modules in four sizes; b) feedthrough modules in four sizes; c) frames adapted to these modules: standard frame P1, perforated frame P2 or frame P3 for feedback modules; solid frame P4 for feedthrough modules; d) module clamps and inserts; e) removable identification tags; f) removable male crimp contacts of sizes 22, 20, 16 and 12; g) sealing plugs.