A gas flow indicator apparatus (10) comprising: a gas flow chamber including at least one transparent portion (30) and at least one opaque portion (36) at least one inlet port (34) at least one outlet port (32) and, at least one gas flow signal means (18) movably disposed within the gas flow chamber. The gas flow indicator apparatus (10) being configured such that when no gas flow is present and/or when a predetermined gas flow rate has not been achieved, the signal means (18) is disposed substantially within one of the transparent portion (30) or the opaque portion (36), and wherein when gas flow is present and/or the predetermined gas flow rate has been achieved, the signal means (18) is moved to be disposed substantially within the other of the transparent portion (30) or the opaque portion (36). Gas delivery devices (12), systems (12) and/or conduits (16) incorporating the gas flow indicator apparatus (10) are also provided in accordance with the invention.
