Just dont buy them , the quality control is not good as a normal branded one. You can have a lot of choice by looking on internet , just find a good brand and buy.
For example i own a prime component pair of wheelset , well they are not a pair of campagnolo or fulcrum but at least they were sold by wiggle or crc , basically i'ts a small brand (i think owned by them) that has quality control and a great support. CRC and Wiggle are two big shops , thats why i have the security that prime brand is not some cheap or problematic brand.
Also i noticed that brand in the last years became a lot popular , you should take a look and get your idea a lot away from china parts.