FiiO EX1 Aerospace Nanotech Titanium Diaphragm in-Ear Monitors, Black Nanotech Titanium Diaphragm Drivers, delivering even power response across all frequencies CNC milled non-resonant full metal body construction, with anodized duralumin for the back half, and stainless steel for the front half. Ergonomic offset nozzle design, with small rounded on-ear driver housing and shallow in-ear nozzles, ensuring long term wearing comfort. High purity OFC copper, intertwined with 250D Kevlar fiber strands, ensuring superior sonics as well as great strain resistance and longevity.