Sears Kenmore UltraFilter 150, 300, 350, 500 & 550, Whirlpool WHER 12 & WHER 18, EcoWater Compatible Fit Carbon Blocks 38476. Sears Kenmore Ultrafilter 150, 300, 350, 500 & 550 reverse osmosis system compatible replacement water filters twinpack. Replacement for Sears item #04238476000 model #38476. Compatible replacement filters for the Sears Kenmore UltraFilter Reverse Osmosis Drinking Water Systems # 38570, 38472, 38572, 38475 and 38575. Prefilter and post filter both included (two filters total). Also fits: Whirlpool WHER 12 & WHER 18, part #WHERF K002-87, EcoWater Compatible Carbon Block Water Filters. Sears Kenmore UltraFilter 150, 625.385700, 42-38476 Sears Kenmore UltraFilter 300, 625.384720, 42-38476 Sears Kenmore UltraFilter 350, 625.385720, 42-38476 Sears Kenmore UltraFilter 500, 625.384750, 42-38476 Sears Kenmore UltraFilter 550, 625.385750, 42-38576 Filters should be changed at least every 6 months.