Note:
Short Axis: refers to the diameter of the short side.
Coating: Aluminum surface and protective film
Material：Glass
Surface Quality:Lamda 1/2

Different short axis lengths,can be used for DIY Newton reflecting astronomical telescopes.   Please select the secondary mirror size according to your needs.

20mm short-axis secondary mirror, suitable for use with 76mm aperture primary mirror.
25mm short-axis secondary mirror, suitable for use with 114mm aperture primary mirror.
35mm short-axis secondary mirror, suitable for use with 127mm, 133mm, 135mm, 150mm, aperture primary mirrors.
40mm short-axis secondary mirror, suitable for use with 127mm, 133mm, 135mm, 150mm, aperture primary mirrors.
70mm short-axis secondary mirror, suitable for use with 203mm aperture primary mirror.

We are a professional manufacturer of optical components, good at producing lenses, prisms, windows, mirrors, etc.   We are also good at coating.   If you need similar optics, please contact us.