1.1 This part of ISO 9170 specifies the requirements and dimensions for terminal units intended for use in anaesthetic gas scavenging disposal systems in accordance with ISO 7396-2. 1.2 This part of ISO 9170 specifies two types of terminal unit according to whether the power device is upstream or downstream of the terminal unit. 1.3 This part of ISO 9170 also specifies requirements and dimensions for the mating counterpart (probe) of the type-specific connection point which is part of the terminal unit. 1.4 This part of ISO 9170 does not specify the ranges of nominal operating pressure for terminal units, which are defined in ISO 7396-2. 1.5 This part of ISO 9170 does not specify requirements for terminal units for use with compressed medical gases and vacuum, which are covered in ISO 9170-1.