According to Ming-Chi Kuo analyst of KGI, a report sent to investors of Apple shows that Apple will not recommend the 4 inch iPhone this year.
Instead, this product will be released in 2016. Looking at the future, this analyst believes that this new 4 inch model will be supported Apple Pay, NFC connectivity, fingerprint sensor and Gorilla new generation toughened glass.
Previously, some rumors supposed that Apple would release the 4 inch model called iPhone 6C. Accordingly, iPhone 6C will have equivalent specifications to iPhone 5S but it will use high quality plastic casing to reduce product costs.