| parameter | windows/filter standard specification |
| material | glass, fused silica etc. |
| diameter | 3~480mm |
| diameter tolerance | /-0.1mm |
| parallelism | <5" |
| flatness(in 25mm area) | n=2, △n=1 |
| surface quality | 20-10 |
| chamfer | 45°, |
| coating | ar film, reflection film, splitter film,ir cut,ito etc. |
* remark：customized is available | |