I use this to set up a shot before setting up my 8x10 camera.
Not sure if this is a Gaoersi or Dayi brand, I bought it a few years ago. They seem to be discontinued now.
Too bad, they were excellent quality items.
Nice anodized aluminum housing and clear optics.
This one zooms from 90mm to 210mm. Just double the FLs for 8x10, or add 30% for 5x7.