Ross I have a friend the just bought a series 60 2005 HR She asked me for the airfilter number. it looks like a eco sm but I am not sure. her name is dee@staplesgroup.com nice gal and excited to have the same unit you do I am greg@rainbowrv.com I own that rv club and live in Romoland I have an old Wanderlodge with a 8v92 . if you are in town look me up we have 50 amps an a shop we use for our construction equipment