In ear headphones also known as earphones or earbuds are a compact and lightweight headphone that consists of two small ear buds, one for each ear that are connected by a wire. These small earbuds are inserted directly into the ear canal for a comfortable and secure fit. Earphones often have high quality speaker drivers in them which provide excellent sound quality they also provide passive noise isolation due to the seal that is created in the ear canal allowing an immersive listening experience. For extra comfort most earphones are supplied with sets of different size earbud covers which enable the user to obtain the best fit and optimise noise isolation. Earphones are available as wired earphones that use a cable with an audio jack or USB connector or wireless earphones which use wireless technologies such as Bluetooth. Built in microphones are a feature on some earphones with control buttons built into the cable which enables users to control music volume, playback and make phone calls without having to remove the earphones. Earphones, due to their small size are extremely portable and can be carried around in small bags and pockets making them ideal for travel and on the go use.