According to the report, an initial letter received from a manufacturer of these colorful shells referred to them as being made for the Apple iPhone 5S with nary a word about a low-cost iPhone or an Apple iPhone Lite. The second letter listed the dimensions of the part as being 5.8cm (width) and 12.3cm (length). Referring back to a schematic diagram leaked earlier by Apple Insider, those measurements dovetail quite nicely with the expected 58.57 mm (5.8cm) by 123.83 mm (12.3cm) size of the Apple iPhone 5S. For the record, the Apple iPhone Lite's schematic revealed a larger size of 59cm x 124cm, which in all honesty is just a shade larger than the iPhone 5S.
But if we go by the preponderance of the evidence, we have the first letter saying that the shell is for the Apple iPhone 5S, and we have the measurement of the part matching the size of the iPhone 5S, even if it is just by a hair. If this is the case (pun unintended), it could the next version of the full-priced iPhone that gives users a choice of colors. And even if the shells are knock offs, as the evidence suggests, they still could be based on information leaked from Foxconn.
Letters from Chinese shell manufacturer