This is a cable that converts Sennheiser IE300, IE600, and IE900 earphones into gaming earphones with a boom microphone, similar to the SteelSeries TUSQ. It has a 3.5mm 4-pole plug. The IE300 in the photo is not included. It allows for both superior positional audio and voice chat. It is unlikely to work with counterfeit IE300s, etc. It includes a mute switch, volume control, and function switch. The boom microphone is a 2.5mm 2-pole type and is detachable. TUSQ microphones can also be attached. This is a prototype, so there may be some rough spots in the construction. Also, since it is different from the finished product, excessive force may cause damage. Responses and shipping may take a long time. Please refrain from purchasing if you are in a hurry.