I ordered this for a telescope I was building. I didn't use it. It is brand new.

GSO's elliptical flat mirrors have the same high quality as their parabolic primary mirrors. Made from optical grade BK-7 glass, all mirrors have a reflective aluminum coating with a reflectivity of approximately 92-93%. The aluminum coating is protected by a silicon oxide (SiO2) over-coating.

Specifications:

Manufacturer part #: AD047

Minor axis diameter: 62.5mm

Approx. major axis diameter: 88mm

Approx. thickness: 12mm

Weight: 4.5oz (128g)

 Any questions please ask.