The Spot Zero Dockside Pre-Filter Kit is a two-stage water filtration system designed to improve incoming dockside water quality before it reaches your onboard purification or washdown system. By removing contaminants, heavy metals, sediment, and particulates at the source, it helps extend system life and improve overall water performance for marine applications. Stage 1 utilizes oxidation and heavy metal filtration to target dissolved contaminants, while Stage 2 captures suspended particles and sediment for cleaner, more consistent water delivery. The complete kit includes replacement filters P/N 252404004 and 252404005.