The UBON Air solo BT-190 is one of the nicest designed Bluetooth single earbud headset in our roundup, and not only does it look good, it also feels comfortable to wear. It's quite as small and unnoticeable as its name suggests, but with such a nice design. The Product to be more and more light weight and have a buttons for switch on/off. Perhaps most importantly, sound quality on this earbud is excellent. This is one of the best Bluetooth single earphone best suited for On the go like Driving, Gym, Running etc. This is definitely a Bluetooth headset worth investing in if you rely on voice-free calls. The earphones have a battery size of 90 mAh and the case has the capacity of 200mAh