The Kettler HR Chest Strap helps you keep track of your heart rate during workout sessions. The Polar T-34 is compatible with a number of Kettler exercise machines and the Polar Heart Rate Monitor. It has a subtle design in a lightweight yet durable construction. It wont get in the way of your exercise routines because you wont even notice its there! The casing is waterproof so you dont have to worry about sweating all over it. In addition, the adjustable nylon strap and transmitter is made out of a hygienic material. The Kettler HR Chest Strap is great for individuals who want specific statistics to better improve their fitness exercises.