At first, I thought the hole by the headphone jack is for the sim card only to realize the sim tray goes in side. I am curious to know what that hole is for because I put the end of a staple in it in an attempt to take out the sim tray(not knowing that it's on the side) and I'm afraid i might have broke something. Also there is a line next to this hole, I would appreciate it if someone told me what this for as well. Thanks in advance.