This is a scan of the letter sent to a participant explaining how and when the activity monitor should be worn. The activity monitor accompanied the letter in the same envelope. The return date was computed according to the dispatch date and the likely time of delivery.

This resource can be downloaded or viewed using the link: activity_invite.png

If you have wget available (typically on linux systems), then you can also obtain a copy using the command

 wget  -nd  biobank.ctsu.ox.ac.uk/ukb/ukb/images/activity_invite.png