150g of polycarbonate and 5 inches of a full-HD screen. Amazing what they'd call a mini these days. Technically, the ZTE Nubia Z9 mini is the compact version of the bezel-free Z9 but size isn't the first thing that sets these two apart.
Source: http://www.gsmarena.com/zte_nubia_z9_mini_review-review-1302.php