Do you have a 2" refractor diagonal (standard or dielectric) or clones that you want to use with your SCT or Mak telescope but cannot? Here is the solution you need! In response to requests from several customers, we now offer just the SCT barrel from 2" Alstar SCT diagonals. Alstar SCT Adapter will let you convert compatible push-in (refractor) type diagonals into a standard SCT diagonal without committing extra funds to a brand-new diagonal. With compatible diagonals, you can simply unscrew the chrome barrel on the telescope end of your refractor diagonal. Then insert this barrel in its place and you can now use your refractor diagonal with all telescopes having a standard SCT thread.