An inhaler for facilitating inhalation of dry powder, the inhaler comprising: a body defining an interior space and including a mouth piece; and at least one annular member (51, 151, 351, 551) within the interior space and rotatable with respect to the mouth piece, the at least one annular member (51, 151, 351, 551) including a plurality of compartments (19, 119, 219, 319, 519) and a plurality of flaps (17, 117, 217, 317, 417, 517), each flap (17, 117, 217, 317, 417, 517) being associated with at least one of the compartments (19, 119, 219, 319, 519), each compartment (19, 119, 219, 319, 519) defining a cavity configured to hold dry powder and including at least one opening configured to release the dry powder when the flap (17, 117, 217, 317, 417, 517) is moved from a closed position to an open position, each flap (17, 117, 217, 317, 417, 517) covering at least the opening of one of the compartments (19, 119, 219, 319, 519) and including an extension (17a, 117a) extending beyond the associated compartment (19, 119, 219, 319, 519) or compartments (19, 119, 219, 319, 519), characterized in that: - at least a portion of the extension (17a, 117a) of each flap (17, 117, 217, 317, 417, 517) is configured to be exposed to an airflow traveling through at least one conduit or at least one hole (45, 145, 245, 345, 445, 545), the conduit or the hole (45, 145, 245, 345, 445, 545) being located next to the respective compartment (19, 119, 219, 319, 519), acting on an underside of the extension (17a, 117a), the airflow being configured to move the flap (17, 117, 217, 317, 417, 517) from the closed position to the open position, and - the powder in the compartment (19, 119, 219, 319, 519) is released or withdrawn by the air traveling simultaneously through two separate paths, namely (i) from beneath and through the hole (45, 145, 245, 345, 445, 545) that is positioned within an air duct and (ii) through an opening and then above the hole (45, 145, 245, 345, 445, 545) and the compartment (19, 119, 219, 319, 519) within the air duct. at least one annular member (51, 151, 351, 551) within the interior space and rotatable with respect to the mouth piece, the at least one annular member (51, 151, 351, 551) including a plurality of compartments (19, 119, 219, 319, 519) and a plurality of flaps (17, 117, 217, 317, 417, 517), each flap (17, 117, 217, 317, 417, 517) being associated with at least one of the compartments (19, 119, 219, 319, 519), each compartment (19, 119, 219, 319, 519) defining a cavity configured to hold dry powder and including at least one opening configured to release the dry powder when the flap (17, 117, 217, 317, 417, 517) is moved from a closed position to an open position, each flap (17, 117, 217, 317, 417, 517) covering at least the opening of one of the compartments (19, 119, 219, 319, 519) and including an extension (17a, 117a) extending beyond the associated compartment (19, 119, 219, 319, 519) or compartments (19, 119, 219, 319, 519), characterized in that: - at least a portion of the extension (17a, 117a) of each flap (17, 117, 217, 317, 417, 517) is configured to be exposed to an airflow traveling through at least one conduit or at least one hole (45, 145, 245, 345, 445, 545), the conduit or the hole (45, 145, 245, 345, 445, 545) being located next to the respective compartment (19, 119, 219, 319, 519), acting on an underside of the extension (17a, 117a), the airflow being configured to move the flap (17, 117, 217, 317, 417, 517) from the closed position to the open position, and - the powder in the compartment (19, 119, 219, 319, 519) is released or withdrawn by the air traveling simultaneously through two separate paths, namely (i) from beneath and through the hole (45, 145, 245, 345, 445, 545) that is positioned within an air duct and (ii) through an opening and then above the hole (45, 145, 245, 345, 445, 545) and the compartment (19, 119, 219, 319, 519) within the air duct. - at least a portion of the extension (17a, 117a) of each flap (17, 117, 217, 317, 417, 517) is configured to be exposed to an airflow traveling through at least one conduit or at least one hole (45, 145, 245, 345, 445, 545), the conduit or the hole (45, 145, 245, 345, 445, 545) being located next to the respective compartment (19, 119, 219, 319, 519), acting on an underside of the extension (17a, 117a), the airflow being configured to move the flap (17, 117, 217, 317, 417, 517) from the closed position to the open position, and - the powder in the compartment (19, 119, 219, 319, 519) is released or withdrawn by the air traveling simultaneously through two separate paths, namely (i) from beneath and through the hole (45, 145, 245, 345, 445, 545) that is positioned within an air duct and (ii) through an opening and then above the hole (45, 145, 245, 345, 445, 545) and the compartment (19, 119, 219, 319, 519) within the air duct.