Silflex™
Materion Balzers Optics designs and produces flat mirrors for use in all mirror applications. Their features are excellent quality, impressive flatness, low scattering and they are easy to use over a wide range of angles and wavelengths because of their consistent reflectivity. Dielectric coated mirrors are extremely durable; they have a long lifetime and can be cleaned repeatedly.
Compare the surface quality of Materion Balzers Optics laser mirrors to that of others and you will find no laser mirror with this convincing quality in this price range.