1Built-in answering button, the wireless distance between the earphone and the neck ring is about 20 cm. 2Suitable for Android phones, tablets, Kindle, e-readers, any portable device with standard 5mm jack, phone, MP3 player. 3Small size, light weight, easy to conceal, bright and clear sound, long battery life. 4Simple and safe to wear, clarity and high strength rope can help you easily remove the headphones from the ear canal. 5Made of high quality materials, durable to use.