Forerunner 45 size: 42 x 42 x 11.4 mm - Fits wrists with a circumference of 129-197 mm. Forerunner 45. GARMIN COACH. SYNCS WITH GARMIN CONNECT. Official Garmin Newly Overhauled Product. Monitors heart rate at the wrist, because a finger on the pulse is so old school.
eBay