Protech RXHF-17 External Filter Rack, 17″ Tuesday, 2019.02.19 J.D. H. Leave a comment Protech RXHF-17 External Filter Rack, 17″ Top Search Terms:protech rxhf-17 (1)rxhf 17 filter rack (1)rxhf-17 filter rack (1) Return to What size air filter for RXHF-17? [SOLVED]