Pentair Max-E-Therm Control Panel Cover Retainer Cap (77707-0009) deltauv A cartridge like this is

A cartridge like this is useful because it helps restore filtration capacity while preserving the dimensional fit needed by the existing filter housing

Matching the correct pre-12/2013 application helps preserve fit and original control compatibility

Supports cleaner and more dependable reel operation

supporting more dependable startup behavior in the heater

Useful during fixture service and reassembly work

Pentair Max-E-Therm Control Panel Cover Retainer Cap (77707-0009) deltauv A cartridge like this isSecure the control panel cover on compatible Max E Therm heaters with this retainer cap. Small hardware pieces like this can make a noticeable difference when the cover no longer stays aligned or seated, especially on outdoor heaters exposed to sun, moisture, and regular handling. This replacement is useful during panel service, cosmetic repairs, or heater restoration work where the cover hardware is incomplete. Replacing the correct cap can help