Need help finding a mod that may have posted here...

Either here or the Keystone site.
Had to do with critter proofing the water entry, tv entry hole on trailers. They used a black plastic plunger cut off and fitted to the entry hole. Think it also had the blue water filter...
Wondering because our city water has sediment which will form at the little screen of the city water connection. Then hooking up my hose, it will begin to drip. Need to yearly pull off the connection and clean the screen.
Thank you.