The water heater generates hot water by heating cold water in the inner tank. If the water quality is not good and contains sediment, particles, etc., after the inner tank is heated to high temperature for a long time, it is easy to produce scale and cause blockage, which may not only cause damage to the water heater, but also affect the shower. experience. Warm reminder: The pre-filter is installed at the cold water of the water heater. It can filter and purify the water from and protect the water heater. Filters sediment, red worms, algae and other impurities to double protect washing machines, , smart toilets, etc. Pre-filtration, anti-scaling and purification of every drop of bath water. The pre-filter can filter most of the particles and impurities in tap water and extend the service life of water-related appliances. faucets: Product features: 40um precision filter/strong, transparent, high temperature resistant and explosion-proof filter cup size: 11 x 8 x 5cm Material: pvc colour: A-blue Package Contents: 1 x Water Purifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.