Upgraded 10% Crosslink Resin Water Softener by AFWFilters. System Features - Fleck 5600SXT digital metered control, Black resin tank, Standard black brine tank with safety float, Chlorine resistant upgraded resin (10% Crosslink), Bypass valve and 1" and 3/4" male connections. This unit has both size options so you can take the guessing out of which bypass connection size you need. Tank comes preloaded for easier install. AFWFilters designed system is backed by a friendly knowledgable support staff that can help answer any questions you may have. Installation instructions provide guidelines that allow most homeowners to install the system themselves, and video installation tips are available as well.