The micro-USB adapter is dimensionally only slightly larger than the lightning plug on the end or your USB to Lightning cable that came with your iP5. If the opening in your case has a little space between the original plug and your case, then chances are good the micro adapter will fit. If you have a number of accessories that use the "world standardized" (not) micro USB cable, then this adapter lets you charge all of your accessories and iP5 by carrying just one cable around. If you don't have other micro USB electronics, this adapter is of little use.