Necklaced: you can pull on the headset with rope and not let headset always on your ear. It can just like a beautiful adornment of your clothing. Easy to be charged: you can charge the headset by computer USB socket directly.( We are the only one to have this function in all bluetooth headset.) Colorful: different colors. Smallest one: Size: 60.5x19.5x10mm Compatibility: both types of bluetooth cellphones (handsfree and headset profiles) are supported Special mute function: switch microphone between mute and talk at will One-key operation: press one key to select the function as you want Clear voice: unique tech to minimize the noise for clear conversation Auto connection: connection to be remained within the valid distance Wearing: adjustable hook for comfortable wearing Long stand-by: 300hours Low power consumption: unique design to allow long time talking Operation range: <=10meters Battery: Li-polymer, 160mAh Weight: about 12g Bluetooth specification: compliant v.1.1