Culligan RV Pre-Tank In-Line Water System Filter. This disposable exterior pre-tank filter ensures clean and clear drinking and cooking water in your camper, trailer, motor home, or boat. It effectively filters dirt and sediment, protecting your storage tank and providing a high flow rate for quick tank fills. The filter cartridge is included, but the hose is not. It is designed for use with 3/4" flexible hose couplings in RV or marine applications. NSF listed and backed by a 2-year limited warranty.