Garmin Forerunner 255s smart training watch; used, good condition, sold without box. Comes with charging cable. Note this is not the music version.  

Used but still with plenty of life, this watch is great for tracking activity and health stats. Battery lasts about a week depending on how heavy the use is. Only selling as I don't get enough use out of it.

Built-in GPS, heart rate monitor, sleep tracker, step counter and multi-activity tracker. I used it for marathon training and found it excellent. 

Length of watch is 22.5cm - see photo. 

Retail price new is £299.