An apparatus for dispensing a metered dose of a product, and a method for using the apparatus. The dispensing device has a charging configuration in which an outlet (112; 212) is closed and a metering chamber (120; 220) is configured to expand to its expanded configuration while receiving product through an inlet (111; 211). It also has a discharging configuration in which the outlet (112; 212) is open and the metering chamber (120; 220) is configured to contract to its contracted configuration while expelling the received product through the outlet (112; 212), thereby dispensing a metered dose of product. The dispensing device further comprises a latch mechanism (140; 240), configured to retain the dispensing device in the charging configuration until the metering chamber (120; 220) attains its expanded configuration. The method comprises actuating an actuator (130; 230) of the dispensing device, to fill the metering chamber, and releasing the actuator to dispense the metered dose of product