According to my surprise, as I have the ATIV S plugged in's bracelet: down nearly two centimeters of air, the bag of the bracelet is too big for the ATIV S! The pressure during the closing of the Velcro ATIV S is indeed pressed sufficiently firmly in the pocket, but by optimum fit as described above, it is miles away. : - \
Since I wear the bracelet on the forearm, there is at least no danger that the unit can fall out; worn on the upper arm could this happen but thoroughly. For me the bracelet remains usable, but it is not really a recommendation, especially as is indeed also advertised here directly with the name of ATIV S.