COROS APEX 2 GPS Outdoor Watch For outdoor athletes who train hard and move fast Next-generation accurate heart rate sensor Connect with all five major satellite systems Dual frequency GNSS support (APEX 2 Pro) 17 days of regular use/45 hours of full GPS (APEX 2) 30 days of regular use/75 hours of full GPS (APEX 2 Pro) 1.2" sapphire screen and titanium bezel (APEX 2) 1.3" sapphire screen and titanium bezel (APEX 2 Pro) Wide range of activity modes and third-party integrations Free global offline maps for on-wrist navigation Full training plan and workout support The main differences between the Apex 2 and the Apex 2 Pro is the pro is .1 inches wider which makes room for a larger screen and battery. Consequently it has greater battery life and an easier to view screen, which is useful if you use the maps.