Use with the Medela Swing Solo pump from a few years back. Did a good job at replacing the Medela valve and membrane. I only pump once/twice every few days so only had to replace the duckbill every couple of months. Did well to draw out the milk. Only reason it lost a star is because to remove, it says to twist it off from the top, and to not press the bottom tip to remove - however, when using with the Medela Swing Solo it is not possible to remove without pinching the bottom tip, so worry is damaging the item when removing it to wash.