I just put my last new HEPA filter in an RK05 that I am working on. There are two styles of HEPA filters for the RK05. The original version is just a box. The newer version has the inlet and outlet plenums as part of the HEPA filter, and connects to the blower and a rubber elbow. The one that I just installed was marked EQUIV 1212175. The DEC part number for the filter is 12-12175.
A quick Google search showed that there are 6 new ones on ebay for $35 each. Just search for the DEC part number 1212175. -- Michael Thompson
