S3+ stride sensor comes in black with a new, firm shoe attachment which guarantees accurate speed and distance measurement. This small and lightweight sensor measures each stride you take, helping you analyze the effectiveness and efficiency of your run.
There are a range of factors that can affect your cycling speed. Obviously fitness is one of them, however, weather conditions and the varying gradients of the road play a huge part too. The most advanced way of measuring how these factors affect your performance speed is with the aerodynamic Wireless Polar CS speed sensor.