Medisana heart rate monitor grey M Mio Link 79425, with its streamlined and lightweight design, will be ideal for monitoring and recording your heart rate during various activities. The Mio uses a technology that was developed in cooperation with Philips Electronics Technologies Research. Two LED sensors and an electro-optical lens measure blood flow in the capillaries. Without the need for a chest strap, you can exercise comfortably. Thanks to its Bluetooth Smart (4.0) and ANT+ connectivity, this heart rate monitor in a wrist band transmits continuous heart rate data to mobile apps and sports devices. It is water resistant up to 30 meters and can be worn while swimming. The LiPoly battery is chargeable by a USB charger.