How adjustable is it really?

It comfortably spans several standard ring sizes. Adjust it with slow, gentle pressure rather than force, and avoid repeatedly opening and closing it to the extremes.

Will it turn my finger green?

Not under normal wear. Remove it before showering, swimming, or handwashing, and dry it after wear — that prevents the reaction that causes discolouration.

It has a satisfying weight that reads as real metal, but it is not fatiguing to wear all day.

Which finish should I choose?

Antiqued silver reads as vintage and pairs with existing silver jewellery. Matte black is more graphic and modern, and stands out more against pale skin.