Nannini 7506 Compact One Optics 1.5 Temples Reading Glass (Blue)

What does the size of the glasses mean? (1.0, 1.5, 2.0, ... etc)?

se puede cambiar los cristales si se rompen???

Can you furnish a replacement crystal arm (temple) for nannini compact?? actually, i don't need the entire arm, even just a hinge will be okay.

Can I order the case only ? Lost it