Kowa TP-105FT Protective Filter

The threading is smooth and the glass sits perfectly flush on the scope, so it doesn’t add any bulk when I’m out birding. It’s already taken a few salt sprays on the coast and the lens underneath is still flawless.

I was a little worried about damaging the expensive fluorite lens on my scope during a trip to the coast, so this filter was a no-brainer. It threads on securely and the glass is completely clear—I can't tell it's even there, but now I have total peace of mind against salt spray and dust.

I was worried about salt spray on my scope during coastal trips, but this filter fits flush and the multicoating doesn't affect image quality at all—really glad I picked it up.