None.
This is just an image that tells time. Please do not plagurize this! This one has water proof features. The home button, speaker and audio jack are connected by blue-tooth so if those get ruined, your iPhone is not destroyed. The Apple logo and iPhone are still stainless steel, but the speaker is covered in a thin lair of rubber. The body and screen are also made of rubber. The volume rocker and power button are by the home button. The home button is also made of rubber, but the power button and volume rocker are made of plastic with a thin lair of rubber over them. The third concept will start being created June 2nd, 2016.