Clicks Rechargeable Wrist Blood Pressure Monitor is a portable, digital wrist monitor intended for use in measuring blood pressure and heartbeat rate with a wrist circumference of 13.5 cm to 21.5 cm. It measures your blood pressure while inflating and detects irregular heartbeats. This device comes with a 3.7V 420 mAh built-in rechargeable lithium battery which is to be recharged using the USB cable supplied.