Interface A: USB Type C Male, Interface B: 3.5mm Microphone/Headset Female, For LeTv 2 , LeTv 2 Pro, LeTv Max, Can be used with New Mac Book Pro New Type-C Cable To Audio Port Adapter 3.5mm Earphones Headset for LeTV Mobiles. Gently insert your headphone/earphone pin COMPLETELY into the 3.5 mm jack till you hear a “CLICK” sound. Works best with 3.5 mm TRRS jack (The one with microphone support). Small and light and easy to carry. Plug and play. For LeEco Le Max2 X820 / LeEco Le2 X620 / Le2 Pro X621/Gionee. Not for phones which already has a 3.5 mm jack. Please continue to use your 3.5 mm jack on your smartphone.