You need to be careful when wearing long-sleeved clothing, as it is possible for the bracelet to catch and open itself while you put on or take off a jacket or coat.
Mechanical ball clasp from surgical steel:
This is a safe clasp which reduces the chance of an accidental opening and loss, however closing the bracelet around your wrist may take a few moments.
The bracelets on rubber bands:
The bracelets on rubber bands are very comfortable, but you need to be careful of items with sharp edges, watches, zips, etc.