Example with Pre-Filter - MKL Series, Glass Fiber 3.0um prefilters, PTFE 1.0um final filter, 500cm2, 1/4" Hose Barb I/O is MKLG030F100D2H2H Prefilter (add before Filter Media in part#) MKL = Standard Grade Example - MKL Series, PTFE, 1.0um, 500cm2, 1/4" Hose Barb I/O is MKLF100D2H2H-E = Polyethylene shell and HDPE media support for gamma