Customize, tweak, and play. Our earbuds work with most handheld Bluetooth® compatible devices and we have created a dedicated Earin app to enable you to customize your Earin experience. - Bass Boost; activate to enhance the low end frequencies. - Balance; control the volume between the left and right earbuds. - Battery Levels; Monitor how much battery life you have in each earbud. - Custom Name; Assign a unique name to your earbuds. - Setup Guide; Step by step setup guide.