According to some embodiments there is provided a replaceable flow tract for use with an inhaler device which delivers at least one substance to a user, the inhaler device comprising a housing shaped to receive the flow tract and to further receive a construct comprising source material from which the at least one substance is released; the replaceable flow tract comprising: a conduit comprising: a first opening; a second opening configured for being in fluid communication with a mouthpiece; and a third opening having an elastic sealing member extending therefrom, the elastic sealing member shaped and sized for pressing against the construct when the construct is within the housing.