Reliant Filter Pressure Gauge (Bottom Mount)

Part # B8823 or 5024001000

Plug with gasket on the side of the Reliant Sand Filter Top-Mount 6-Port Multiport/Key Assembly for S116T / S119T / S124T
  (Used for Pressure Gauge insert on multiport)

Items # 7 & 8 (on diagrams)
See Pictures for Measurements