Cessna Radio Cooling Plenum Kit P/N: AK182-124P. Included with an aircraft we purchased. We do not need these. These are designed to be mounted behind your instrument panel, to route air around your radio/avionics stack. Please see all pictures. A bit dented up and they have a little corrosion but could certainly be cleaned up and used. Nonetheless, these are hard to find. This is the best deal on eBay. Buy it now!