I purchased this KX 155 Nav Com 7 years ago from Avionic Unlimited at Conroe Texas with the proper release certificates for both units. Thinking my Narco MK was going bad, we found out it just had dirty connections. We clean the contact points and reinstalled it and it was just fine. I put it in dry storage in my home tightly seal and wrapped in bubble rap thinking I might need it some day. I sold my airplane July 1,2018 and I no longer have a need it. The N number on the rack indicated it cam out of a 1978 Cessna 172N. All the wiring is intact as far as I can tell. The dial and face on both units are almost perfect with no scratches or fading. Serial numbers are high Nav Com # 116573, 209 # 51369.