Problem after a few hours on the wrist small superficial skin burn because of the bracelet. Random timing issue with Samsung galaxy s5. Documentation ridiculous and do not explain the whole program and the results of runtastic me. This morning with the time change I discover a bug in the sleep time, it gives me sleep 9:07 p.m. instead of 10:30. Price is interesting but too limited functions. I'd rather pay more but have the heart functions, stopwatch, gps ... has integrated the watch. Otherwise it is a good commodity.