Semi-in-ear design that help reduce outside noise and keep you connected to your surroundings while listening to music or taking calls. Unparalleled sound quality and call clarity. Noise reduction technology can reduce environmental noise and echo, ensuring that you will not miss any rhythm and enjoy music anytime, anywhere. Dual digital LED power display outside of the case is to show the power level for charging case and earbuds. When you put earbuds into the case, then earbuds will start to be charged. Bluetooth headset is sweatproof and light weight. Ergonomic in-ear design. They do not easily fall from the ears and stay in place. They are very suitable for sports, running, driving, exercise, fitness, relaxation, travel, etc. QTY over 2500 ship by sea.