Wall mount pack: Honeywell Home Evohome ATF600 and ATF800. Suitable for 3rd generation of the Evohome Controllers. Product specifically states the ATC928G3000. Comes with power supply and is fairly easy to fit. The design is very simple and straight forward. Just screw it to the wall and you're good to go.
Be careful though when mounting / fitting, as some buyers have said the back plate is quite fragile and not the best quality. But once fitted it does not have to be messed around with anymore so should sit trouble free for years to come. It should really have been made thicker to begin with in all honesty.