1. In cell (4) you also get the name of the file (in this case 'Stuka'). The file extension depends on the version you download.
2. All the PNG files are on transparent background. Usually all the windows and cockpits are semi-transparent (so you should see through it).
3. OpenTx users, file's name must be 6 characters or less (excluding extension) in the latest version. If you use more, the files won't be showing.
4. Of course, the X9 icons can be used on X9D, X9D+ and X9E radios.
5. If for any reason you want an higher resolution picture, you can still click on the model picture (1). You will then get a new screen.
You can right click on main top picture and choose 'Save image as...', And voila.