Born for Sport
To make the band staying securely on your wrist, an extra loop was added at the end of the band. Meanwhile the nub underneath the loop is to keep the band in place. That's what we called double protection.
High quality stainless steel buckle, free from rust, will not fall off or become deformed. It helps to protect the band from coming loose and falling off effectively. There is nothing to worry about when running, hiking, swimming, exercising, etc.