Although it is done through the CTT, or with some connection/tie-in anyway, it's there for all cyclists. The wristband being particularly useful for those that race as you carry as little as possible when racing, a simple phone call and someone can get all your emergency contact details, medical details etc.
In TTs the organiser has all the entry forms so can indentify you from your number and then match up the form and use the details on that, but I don't think this does any harm and will probably get the wristband ahead of next season.
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