A lot have been spoken about the possibilities of Apple releasing a low-cost iPhone and a multitude of rumors have been doing the rounds about the what to expect from such an Apple smartphone. Adding more to the rumor pile, it's reported that the budget iPhone will have a 4-inch display, matching the size of the iPhone 5. This defies earlier rumors indicating that the low-cost iPhone will feature a larger 4.5-inch display.

There is a good chance that this rumor may turn true as it comes from Ming-Chi Kuo of KGI Securities, a reliable source who has made accurate predictions about Apple future products. Apple had apparently decided the specs for a low-cost iPhone way back in 2011, and the company is unlikely to abruptly change them due to a market shift toward larger screens in the 5-inch range, Kuo shared the details with Apple Insider.

The less-expensive Apple iPhone will come with a super-thin plastic casing mixed with glass fiber, Kuo predicts. Such a material will make the device thinner, lighter and stronger than typical smartphone plastic casings. According to Kuo, the thickness of the handset will be between 0.4 and 0.6 millimeters which is thinner than the average plastic casing at between 0.7 and 1 millimeter. Similar to Apple's iPod lineup, the budget iPhone will come in a range of colors, possibly in four to six options.

Apple has reportedly approached Foxconn as well as Green Point of the Jabil group for its strong and thin iPhone plastic casings. Building casings and assembling the phones will be done by Hon Hai, parent company of Foxconn, while Jabil is expected to provide its casings to Pegatron, which will assemble the remaining iPhones. It solidifies his earlier view that Apple is likely to diversify manufacturers for both its low-cost and legacy iPhones.

Apart from the budget iPhone, Kuo predicts that Apple will release an updated premium 'iPhone 5S' later this year. "He has previously revealed that the next high-end iPhone is expected to include a fingerprint sensor under the home button that will eliminate the need to enter passwords and potentially add new functionality such as secure e-wallet transactions through Passbook," the report said.