The filter treads into the fresh water tank at the very bottom/side and the drain line threads onto the filter housing. Your fresh water fill tees into the drain line so it back fills the tank and it is only a screen filter. The clear plastic cover screws off to clean the screen. It is best replaced on a hoist if you can use one, but I have replaced them with wheel ramps, but laying on the ground is not my thing any more. This location is for 1994 to 1998 roadtrek's, on the Dodge chassis, that I have personally changed, and location may vary for other models, but the two different filters on the shelf were for a number of different years and models.
Good luck.
