I use the castle for my gym because I do not always carry around a key. The castle is lightweight and portable. The strap (or wire) is enough for a suitcase and for the gym from perfect, unbreakable, however, the relatively thin wire is certainly not. I bet you can durchknippsen the strap relatively quick and easy with a simple pair of pliers. The handling is easy, you can just change the numerical code and it is sufficient for my purpose from absolute.