Eye Hardshell:~ This mirror clamps to the lip of Hard Shell helmets. The maximum opening of the clamp is approximately 1/2 inch. The clamp can also attach to the visors of many helmets. The glass mirror is 1 1/2 inches in diameter & it is laminated into the mirror shell making it shatterproof . This doesn't mean that it won't break. If you hit the glass with a hammer it will break --but the glass fragments will not come out of the plastic shell.
• Aluminized reflective backing
• Glass mirror is 1 1/2" in diameter