SoundBot SB552 Behind the Neck Wireless Bluetooth Stereo Headset, Black One size fits all secure fit flexible and bendable memory frame technology allows maximum comfort and portability Ergonomic human engineering design with behind-the-neck and over-the-ear form factor Enriched crystal sound for music streaming and handsfree talking with 2 x 14.5mm powerful speaker driver Incredibly ultra lightweight (17 gram or 0.6 oz) for use on the go without tangled cords Sweat resistant premium silicon built for sports active users. Built-in microphone and controls for phone calls, volume, and music playback.