This deionized water system is designed for the final stage of car washing to help deliver a spot-free finish without wiping. Its 10 L mixed-bed resin helps remove dissolved ions from water, while the built-in bypass valve allows easy switching between tap water washing and filtered final rinsing. A TDS meter helps monitor water quality so you know when resin replacement is needed. The unit is suitable for cleaning cars, RVs, motorcycles, windows, and solar panels.