What is iPhone Bypass? Should I buy it? Why is the selling price as cheap as giving?

Besides the genuine iPhone, the portable iPhone, the Refurbished product and the iPhone Certified Pre-Owned (CPO), a new type of iPhone is also widely sold on the market, which is the iPhone Bypass. So what is iPhone Bypass? How to recognize iPhone Bypass, what are the limitations? Should i buy an iPhone Bypass? All will be answered through the following article!