ResMed Astral Series Clinical Manual page 44

There are three circuit adapters:
Adapter
1 Single limb leak
2 Single limb
3 Double limb
(Astral 150 only)
A Learn Circuit should be performed after any change of circuit. Astral will provide accurate therapy as long as the Learn Circuit
is completed. Refer to Learn Circuit (see page 44) for further information.
For use with
Single limb circuit with intentional leak or mouthpiece circuit
Single limb circuit with expiratory valve (expiratory valve integrated into the circuit)
Double limb circuit (expiratory valve integrated into the adapter) OR single limb circuit with
intentional leak or mouthpiece circuit
Circuit options
English 37