Polar RC3 GPS Sports Watch Wristband Size : 9  . NOTE - Measurements taken from the LAST HOLE to the END OF RUBBER next to buckle (not from end to end). Wristband Size : 9  . NOTE - Measurements taken from the LAST HOLE to the END OF RUBBER next to buckle (not from end to end). All in one GPS monitor tracks your speed, distance and route using the latest GPS technology (SiRFstar IV) Slim and lightweight design with rechargeable battery (12 hours in continuous use with GPS on) Unique Polar Smart Coaching features such as Running Index and Training Benefit analyze your training (optional H2 heart rate sensor needed) Shows GPS - based altitude during and after training Compatible with running and cycling sensors plus polarpersonaltrainer.com, our free training diary where you can download endurance training programs