3/4" In and Out tank closure 890S or D7171.
Fits standard tank openings.Includes the top of tank o-ring
( V3180 - Note: old models used o-ring 3410381 ) and the 13/16" distributor o-ring ( 3410244 ).older ...... fits around the threads 10381
newer ( since 2011 ) ........ seals to surface V3180
Commonly used on whole house carbon tanks and acid neutralizing tanks.
If you need the Top Distributor with this new head, you can use the "twist and snap" into place 13/16" version ( our PN MD1203-01 )