Propur Water Filters 2 - 5 ProOne G2.0 SlimLine Filters ProOne G2.0 5 Slimline for Scout and Prepper Traveler Recommended replacement: 6 months per filter.9 months per pair All-In-One Water & Fluoride filter - Ideal for use with just about any water source No priming required and no additional filters necessary to remove fluoride Meets NSF/ANSI standards 42 & 53