Buy from Amazon.co.uk : http://www.amazon.co.uk/gp/product/B00DM8AQKQ?tag=1001consej026-21

Weartech Men's Gow Smart Sports T-Shirt (Intergrated Cardiac Sensors) - Grey/White Large

Smart Sports T-Shirt with Integrated textile sensors to measure heart rate calorie fat and carbohydrate burn
Compatible with GOW Heart Rate Monitor Sold Separately or any other Smart Bluetooth 40 Heart Rate Monitors
GOW personal training App available from Apple and Android App Stores iPhone 4S5 Samsung Galaxy S3S3 mini S4 Note2 Compatible
As easy as 1 Put your GOW Sports T-Shirt and Sensor on 2 Turn on GOW Training App and 3 Go
Seamless fabric enables ensures maximum comfort moisture release and avoids chafing Technical yarn with Bosy thermoregulation