My set was missing the smaller mirror. The only option is to return the larger mirror but I already have installed it. The seller reached out to me after my negative review and sent me a replacement. Both mirrors are in perfect condition and the seller was responsive so I'm giving them 5 stars.

Used for a Hadley Telescope, worked very nicely. Very nicely packed and inexpensive.

I rebuilt an almost free goodwill reflector telescope using these mirrors. They were a perfect fit and an inexpensive way to bring a telescope back into service.

I had a bad experience with a different amazon seller- the ronchi test showed severe zones in the sphere, some of the worst I've ever seen.This mirror is great, with only slight undercorrection and some TDE at the edge- this is time consuming to remove and largely doesn't affect the view, and can easily be masked. In some cases, like this one, it may even be beneficial to have a slight bit of TDE (but it gets complicated). Overall this is a great buy for 30 dollars.Attached is my outside ROC ronchi test of this mirror, Blue, and a perfect ronchi test, black and white. You can be confident in this purchase.

Works well