what is on the back of rugby players shirts

The lump or box on the back of rugby players shirts is a GPS tracking device. This device is part of a sophisticated biometric tracking system used by coaches to track a variety of data, including distance covered, speed, and heart rate. The GPS pod is designed to sustain collisions and is cleverly positioned to avoid injury to the player. The device provides valuable data that can help both professional and amateur players improve their performance. The GPS tracking device is kept in place in between the shoulder blades in something called a "Bro," which works in much the same way as a female athlete's sports bra.