RO Flow Restrictor 450 ML Compatible with all the RO Membranes,......Suited for water filter Purifiers for dolphin,kent,Grand,Aqua Guard and many RO models-Can be used in any purifier Model - Counter Top, Desk Top,Stand Mounted,Wall Hanging,Under Sink..... In any RO Unit,Flow Resistor will create back pressure on the membrane and allow the membrane to produce more purified Pure,Tasty,Sweet water.............. Flow Resistor Comes in Various Sizes, but most of the RO Technician prefer 450 ML Size for Consistency. If the Membrane and FR are not changed frequently,......... Foul Smell may arise from the Water Filter due to Clogging............. Also Ideal Product for Study Purpose/Research/Project Design/Demo Work who would like to Explore the Functioning of the Various RO Components in an RO Unit by Cross Section Analysis..............Pack Contains : - 1 Pcs of 450ml RO Flow Restrictor/Flow Resistor Suitable for all RO Models