These are 1500 x 1500 pixel images, aimed mainly as page backgrounds to be used on UniServity's Life learning platform. However educational establishments are welcome to use them as backgrounds images for PowerPoint presentation, IWB files - or anything that they can think of! They should not be use for any commercial purpose without prior permission.
To use them - click on the chosen image. Right click over the larger image which should open in a new window. Select "Save Image".