Polar 91053153 Clip-on activity tracker Wireless IPX7 Black activity tracker

Bluetooth, 3V, 2.402-2.480GHz, iPhone 4s, Black The Stride sensor Bluetooth® Smart is ideal for runners who want to improve their technique and performance. You get to see information about your speed and distance on your training device, whether you're running on a treadmill or the muddiest trail.

- Measures each stride you take to show your running speed and distance
- Helps improve your running technique by showing your running cadence and stride length
- Shows how your running performance changes with Polar's unique Running Index feature
- Fits firmly on your shoelaces thanks to its compact size
- Shock and water-resistant to handle even the most demanding runs
- Compatible with iPhone 4S and later