New Replacement Air Filter for use on OSSA models using the IRZ air box. SDR, PIONEER, WILDFIRE, PLONKER and others. TECH NOTE: (YOU WILL NEED TO USE SOME KIND OF WATER PROOF GREESE (EG. BELLRAY) AROUND FILTER TO MADE A NICE AIR TIGHT FIT). MANUFACTOR AND SELLER MAKE NO CLAIMS AS TO THEIR FIT OR FUNCTION. SPECIFICATIONS MADE FROM 30+ YEAR OLD PARTS. FOLLOW UNI-FILTERS RECOMMENDATIONS FOR CARE OF THE FILTER.