Diameter: 76 mm
Focal length: 350 mm
Set of an objective mirror and a secondary mirror.
The 76 – 350 spherical mirrors, aluminized and protective film are good materials for telescope enthusiasts.
Tips for cleaning mirrors:
First blow off the dust that can be blown away with a balloon, then gently wipe the mirror with good quality degreased cotton after touching alcohol.
After drying, look at the light source from the side to see if there are any cotton silk or water stains left on it.
Otherwise, gently wipe the mirror with some good quality cloth (be careful, otherwise).
It will have an impact on your telescope.