Which model loupe do I need ?

我需要哪种类型的双目放大镜？

You would need a jeweller's loupe the size of the Sun to grade this diamond.

要评价这颗钻石的等级，需要使用像太阳那么大的珠宝商专用放大镜。

This loupe is a low magnification microscopic system, it can enlarge very small structures and get clear and upright images.

这个放大镜是一个低倍显微镜系统，它可以放大极小的结构，从而得到清晰直观的图象。