If you’re in need of 634-3020-004 or Avionics, from Rockwell Collins, Aerospace Unlimited is your one stop shop. We carry Fixed Wing parts and other items as Shim. If there is something specific that you are searching for, browse by Aircraft Model part number such as 634-3020-004 in our catalogues to find what you need. 13499, engines, fasteners are just a few of the 6 billion items that we can inventory. And thanks to the various shipping locations that we have, we can ship almost anywhere. Contact us today to get an immediate quote!