Very light and very comfortable front wide elastic headband. Impossible to lose the lamp is forgotten during a race without problems. Power entirely correct, excellent power adjustment according to light reflected or cross (car). Almost immediate change following the gaze (- 1s to fit). Delighted with this purchase and would recommend it for activities like running / work / outdoor sports in the evening or at night. Resists rain. Reacts a little steam produced by blowing during a race (less power) but significant problem. Not used programming via the application (the default setting is not very good).