Polar RS300X Sports Watch Easy-to-use heart RATE monitor guides you to train at the right intensity Includes H1 heart RATE sensor chest strap for continuous, accurate heart RATE. Uses coded transmission to avoid cross-talk with other heart RATE monitors nearby Built-in fitness test helps you can Track and monitor your fitness improvement Displays accurate Calories burned and records last 16 training sessions and your last 16 weeks of training Compatible with S1 foot pod and G1 GPS sensor for speed and distance (not included, sold separately) Wristband Size : 8.5  . NOTE - Measurements taken from the LAST HOLE to the END OF RUBBER next to buckle (not from end to end).