The Vevor deionized water system is designed for the final rinse stage of car washing to help deliver a spotless, air-dried finish without wiping. It uses 2 x 4 L of premium mixed-bed resin to remove dissolved ions such as calcium and magnesium from the water. A built-in TDS meter helps monitor water quality so you can maintain effective purification and replace resin when needed. The portable trolley design with wheels and dual handles makes it easy to move around during use. It is suitable for washing cars, RVs, motorcycles, windows, and solar panels.