iSpring WSP50ARB Spin Down Sediment Water Filter, Reusable with Touch-Screen Auto Flushing Module and Built-in Housing Scraper, Brass Top Clear Housing, 50 Micron

50 micron. I upgraded to the 50 micron ispring auto flushing model about a year ago now. Mine drains every 3 days. After the spin down filter I have a 25 micro and 5 micro whole house filter. I change those about every 3 - 4 months.