[First Defense of Whole House]OSWNKW-05 Whole House Pre-Filter, with a 40-Micrometre pore size stainless steel filter, is designed to prevent particles such as sand, rust, limestone and sand from entering your home [Prolongs Water Facilities' Lifespan]Protect your household plumbing, kitchen and bathroom equipment from particulate impurities in municipal water, which can block water taps, shower nozzles, water heaters, washing machines, RO water purifiers and other water-related equipment. [Water Pressure Drive Auto-rotating Scraper Backwash]Once prefilter gets saturated with sediment, You don't have to dismantle all your tubes and pipe fixtures when you need to clean our sediment filter, all you need to do is One key Turn right to open the sewage ball valve, The water flow drives the Propeller at the bottom of the Scraper, achieve an automatic rotating effect, and make the filter cleaner. [Monitor Water Pressure]Built-in water pressure gauge, monitoring real-time water pressure at any time, family members can take measures to deal with abnormal water pressure. To ensure the safety of water, general household water pressure range: 0.1MPA-1MPA. [Featured Material] The 40-Micrometre filter mesh is made of SUS stainless steel, and the head of the main body is made of lead-free brass, and the service life is more than several years. The heavy-duty food-grade transparent housing made in Germany does not contain BPA and has passed the water hammer test of 150, 000 cycles and the highest pressure test of 1000 psi. Specification: Model: OSWNKW-05Water treatment machine Type: Pre-filterFilter D-DN20 with pressure gauge Filter Maintenance: Clean the filter elements every 15-30 days, and replace the filter elements every 1-3 years according to the water quality. Material: Food grade explosion-proof PC Cover, lead-free copper