Reliant Filter Bottom Mount (Lollipop Style) Pressure Gauge

Part # B8823 or 5024001000

Bottom Mount (Lollipop Style) Pressure Gauge for all Reliant Filters 
    Including Cluster Cartridge C3425 / C3525 and Sand Filters F116T / F119T / F124T / S116T / 119T / S124T / S226T / S531T

It is recommended that you wrap the bottom brass fitting with Teflon Tape about 5-6 times before screwing it to the top of your Filter Lid/Top. This will ensure a tight seal and no leaks.
Teflon Tape: Part # B8538

If you are looking for the BACK MOUNT (Cake Style) Pressure Gauge:
Back Mount: Part # B8824