These are some common tools used to work on this device. You might not need every tool for every procedure.
Background and Identifcation
The Fenix 3 HR was released by Garmin in 2015 and is distinguishable from the Fenix 3 model by being made of metal instead of plastic and the incorporation of the optical heart rate sensor.
The Fenix 3 HR model has a 3 cm display with 218x 218 resolution and weighs approximately 86.1 grams. This model also boasts a 16 hour battery life in GPS mode and up to 40 hour battery life in UltraTrac mode.