While most dedicated heart rate monitors get strapped to your chest, Coros has gone in a very different direction. Instead, Coros designed this device to be placed over your upper arm (above the elbow). As Coros explains it, your upper arm has an ample amount of deep tissue and blood flow, allowing their heart rate monitor to gather incredibly accurate heart rate data.
The Coros Heart Rate Monitor is a rather simple product. There are no buttons to mess with, making setting it up an absolute breeze. It’s essentially a small rectangle attached to an elastic band that is held securely in place with Velcro. The Coros Heart Rate Monitor measures 42.5 x 28.4 x 9.9mm and weighs only 19g.
The band is made from a combination of polyester fiber, nylon, and spandex. It has a minimum circumference of 7.09 inches and a maximum circumference of 12.6 inches.
Looking at the Coros Heart Rate Monitor itself, it looks exactly like the bottom of a standard fitness watch or smartwatch. Inside it has 5 LED lights and 4 photodetectors to track your blood flow. There is an LED indicator light along the left edge that lights up green when it’s active.
The charging cable has a USB-A port on one side and a proprietary connector on the other side. At about eight inches, the charging cable itself is incredibly small. It’s so small that depending on your situation, charging it can be slightly annoying.