Cooler Master B500 v2 PSU
The Cooler Master B500 v2 PSU is a cheap ("budget") power supply unit from Cooler Master. It has rather poor voltage regulation but works fine as a PSU.
First of all, the fan on this power supply unit makes that annoying "humming" sound that are common to every single Cooler Master fan motor on every fan that comes with all of their products. You'll know what kind of garbage fan it has if you heard the fans on any brand new Cooler Master case like the HAF 912 or the N600.
Secondly, this fan becomes really loud and problematic after just a few months of use. The fan starts making a louder and louder annoying clicking sound which is barely drowned by a GPU running it's fans at full speed.
In bullet summary: It's a cheaper PSU that's made with cheap parts and the fan is specially cheap. This PSU is not worth buying because you will be wanting to buy another one after just a few months.