Syba OG-AUD63049 NC-1 COBRA 2.1 Dual Driver Headphone with Built-In Amplifier and In-line Microphone, Black and White Model Internal headphone amplifier helps power the dual driver, 30mm and 40mm driver, within the headset. Controls for both Volume and Bass level. Driver Impedance: 30mm 32 Ohms and 40mm 32 Ohms Gold Plated 3.5mm Jack 4-pole Connector (Compatible with Smartphones, and Tablets) Cable Length of 47-Inch with Twin 3.5mm Adapter for PC and Laptops is included Oblanc Deeper Bass with In-line Microphone white