Anti-Tightening:The Strap Extender can help to keep your tighted when you work and doing exercise and prevent any harm and pressure to your ears from the cords. Adjustable Length: The Strap includes 4 adaptable card position, which can effectively help adjust your to fit different face size. can also be useful for kids when keep your band at the smallest card position. Ear Scratch Alleviating: Compatible with most of the ear-mounted on the market. You can change the buckle in seconds and reduce the pressure and ear fatigue on the ears. The Strap Extender is good for current office workers when you work for a long time or doing exercise, bicycling, help protect your ears. The Package include 5PCS hooks.