Abatement Technologies PRED750 Filter Starter Kit Featured Ductless The RPM RT1 is the permanent MERV 6 The RPM RT1 is the permanent This bundle is the correct OEM filter set for the following Mitsubishi mini split indoor units: High particulate environment Approximately every 72 hours Medium particulate environment 3× per month Low particulate environment Monthly or when filter indicator light activates Use only Abatement Technologies OEM replacement filters to maintain equipment warranty and rated performance F621 × 12 1st stage coarse pre filter 15 1 2" × 16" × 1" FIBER TRAPPER® — captures large particles before they reach the pleated and HEPA stages change monthly H502 × 6 2nd stage pleated pre filter 16" × 16" × 2" MERV 8 — captures medium particles and protects the HEPA filter change every 2 months under normal conditions