"V5" (Version 5) was one of the last iterations of these calculators. It was designed to support:

Typically, entering an unlock code does not void your warranty or alter the system firmware. How to Use the Calculator (Step-by-Step) Codes Calculator for Huawei – Apps on Google Play

Such calculators became popular around 2012–2015 when Huawei used a less complex algorithm to generate unlock codes for some of its older feature phones and early smartphones. The tool claimed to work without needing to contact the carrier or Huawei directly.

In May 2018, Huawei abruptly shut down its official bootloader unlock service. Shortly after, they patched the vulnerability that allowed third-party calculators to generate codes. The "V5" calculator only works on devices manufactured and running very old security patches.