I am not exactly sure, but “inlet sinker” has been used as another name for stainless steel sparging stones or stainless steel inlet filters. This term may be used since the stones are heavy and sink to the bottom of the mobile phase inlet bottles.

Please note the specifications for the filters (length, OD, and ID) are given in US, not metric.

Click HERE for Mobile Phase Filtering including Sparging Stones (inlet sinkers).