This helps stabilize your iphone5 when you are using the 30pin to lightning adapter.
Ever feel uncomfortable when your iphone 5 has very little holding it in place during the use of the 30 pin to Lightning adapter? This is the missing piece of plastic the adds stability to the iphone 5 when using the adapter
After printing you have to remove the .8 mm piece of plastic that is in the way of where the phone goes. The thin wall of plastic is for support while printing. It removes easily with a razor cutter especially if you can cut the middle first. Sorry about this part but it makes for a good print.
It is a pretty tight fit when you put the adapter into the plastic piece. Once it is in I don't worry about it coming out.
Depending on your print tighten with tape or file a little out till it fits tight.