Fangrui Product Details This Coffee Filter Fits Your Filter By Entering Your Model Number. This Applies To Ca6903, Not Ca6702.easy To Use: Lone Exchange Resin Effectively Prevents Limescale Deposits. In Addition, The High-quality Activated Carbon From Coconut Shells Can Absorb Residual Chlorine, Which Improves The Taste Of Your Coffee (tested By A Third Laboratory).no Limescale To Use: You Do Not Need To Decalcify Your Coffee Machine. This Coffee Machine Filter Prevents Limescale By Replacing The Calcium And Magnesium Ions Contained In The Water, And Has Been Tested By A Third Party Laboratory To Extend The Maintenance Interval Of Your Coffee Machine To 3 Months.our Filter Is Tested And Certified By Tüv Süd For The Reduction Of Chlorine In Water.the Of The Product: Espresso Machines With Aqua Clean Filter Ca6903/00, Ca6903/01, Ca6903/99, Ca6903-00, Ca6903-01, Ca6903-99, Ca6903 Cartridges.