They ship and distribute NZ products into China.
Someone else might be able to clarify the details, but I believe the NZ customers are websites and daigou (
https://en.wikipedia.org/wiki/Daigou) who sell products to China - they pay QEX who then buys, packages, ships the product to China (clearing customs) and then distributes it from there. Predominantly infant formula and health suplements I assume/believe.
Their magic sauce is the ability to do all of those things, rather than being another Fedex or DHL, and a "knack" for getting through the customs process.