Yes, you can easily switch between the 2 phases using the ‘phase’ toggle button. When switched on, the 2in1 Electric Breast Pump will start in ‘let-down’ phase which lasts for 2 minutes, at which point it will automatically switch to the ‘expression’ phase. If you achieve let-down prior to the 2 minute automatic switchover, you can push the ‘phase’ toggle button and you will go into the expression phase. Similarly, if you wish to return to the faster ‘let-down’ phase during your pumping session, you can push the ‘phase’ toggle button and the pump will switch back into the ‘let-down’ phase.