Plastic Bowl Assessory - used w/ these filters: WF10013 - WF10014 - WF10015 - WF10016, WF10021 - WF10022 - 33992 - 33693 - 33935 - 33723 - 33970 - 33778 - remove sensor drain from filter, install bowl, then place sensor drain in the bottom of the newly installed bowl - if sensor drain required, order part # WS10004 separately - NOTE: drain sensor port # WS10004 has a sensor port opening in the middle of the drain - sensor size is 1/2-20