Digital (ANT +) Chest Strap for Heart Rate Measurement The Heart 2feel X chest strap uses the ANT + digital transmission method at 2.4 GHz frequency, ensuring interference-free transmission of heart rate data. This makes it suitable for all digital bicycle computers: macro x, macro high x, urban x, urban high x, navi2coach twist und coachsmart by o-synce The comfortable and seamless softbelt convinces by its wearing comfort and is worn like a second skin. The required battery for the transmitter is included in the delivery.