Rucks are designed to be worn high on the back, but Training Sternum Straps help reduce jarring and movement while rucking. They also help redistribute weight across your chest and shoulders for added comfort.
The strap adds an additional cross-body connection that can double as a quick carabiner clip-in point.
Training Sternum Straps are removable and adjustable, and they attach via clasps to the MOLLE webbing on the shoulder straps for extra stability.
Sternum straps can take a bit of practice to adjust. Below are a few videos that walk you through how to install, remove, and adjust the strap so it fits both your body and your ruck properly.