TechPowerUp takes a look at the 64 Audio U4s In-Ear Monitors
A quote from the article:
64 Audio lowers the entry barrier to its universal-fit IEMs with the all-new U4s hybrid driver set. It uses a 1 DD/2 BA/1 Tia driver configuration paired with four sets of Apex modules, including the brand new m12 modules, to put out a smooth and customizable sound signature in a very comfortable form factor to be highly compelling in its price range.64 Audio U4s In-Ear Monitors Review