Mapleson's classification of beathing systems

Circuit	FGF - spontanous	FGF - controlled	Notes
	0.8 - 1	2 - 2.5	In order to remove the APL from close to the patient, Lack circuits may be used. These may be coaxial or parallel (below)
	1.5 - 2	2 - 3
	1.5 - 2	2 - 3
	2- 4	0.7	The coaxial version of this circuit is the Bain circuit
	2- 4	2 - 4
	2 - 4	2 - 4	This is the Jackson-Rees modification.