The 15 micron, sintered metal tip produces tiny air bubbles for optimum gas distribution. The “A” dimension listed allows for placement in different ports of the headplate. NOTE: Replacement O-Ring listed is for M10 connection. Stainless steel components are manufactured from 316L with an electropolished surface finish of 20Ra or better.Like-for-like replacement parts for Applikon Biotechnology and Broadley-James brands of bio reactors.Applikon is a registered trademark of Applikon Biotechnology, Inc. Broadley-James and Broadley-James Corporation are registered trademarks of Broadley-James Corporation.