William Optics RedCat 71 348mm f/4.9 Petzval Apo astrograph
The WO Cat71 is a 71-mm f/4.9 refractor using a Petzval design with a doublet front element incorporating FPL-53 glass, plus a single central element and a single rear lens. By this design, our WO Cat71 provides a flat image plane without any additional flattener and the image circle is over 45mm. WO Cat71 is designed primarily for imaging, making it an astrograph.
I am a beginner and bought this to make sure my scope was set up correctly. The slight problem I had was that the batteries supplied where dead but when I was able to buy new ones it worked very well.