Bahtinov focus mask for Celestron 11" SCT with Fastar or Hyperstar READY, FP412H Farpoint Focus Mask - Celestron 11 SCT (Hyperstar/Fastar) fits Fastar/Hyperstar READY C11 SCT's. It does NOT fit with the Hyperstar or Fastar camera installed. That will require a different mask, coming soon. Bahtinov Focus Masks make focusing for astrophotography easy; instructions included Works with all DSLR cameras or CCD imagers Simply place the Bahtinov Focus Mask over the end of your telescope Made in the USA by Farpoint Astro