Garmin's Fenix 5X Sapphire (slate grey) multisport watch is a powerful health and fitness platform. This is a used watch in excellent condition, and the Sapphire version was their extra-durable stainless & titanium watch that also includes WiFi and Bluetooth to sync activities and notifications, optical heart rate, compass, and multi-constellation GPS, Glonass, & Galileo satellite tracking. The watch is durable and waterproof for swimming and other watersports. It is a full-function bike computer and pairs to numerous power meters, cadence, and speed sensors. As a running platform it pairs to heart rate monitors and running pods, and for triathlon it works with swim-specific heart rate straps (that store data locally to overcome the limitations of wireless signals in water). It supports both ANT+ and Bluetooth sensor pairings. Complete specifications are here: https://www.garmin.com/en-US/p/560327#specs.
This used watch shows very little wear and tear, works perfectly and has never presented me with a problem, and includes USB (USB-A) charging cable and standard watch strap (26mm quick change - many aftermarket options and materials are available; I used it with leather and titanium bands during business meetings).