Whether it is a secondary water supply or not, we recommend that every household use a pre filter, because there will be great hidden dangers before the tap water enters the household faucet, such as pipe pollution, which is exacerbated by the secondary water supply. If a prefilter is installed in the home, it can effectively filter out large particles in the water. The filter precision of Nobana series prefilter reaches 40 microns, providing clean water for wading appliances, effectively extending the service life of household appliances.