Will a new, cheaper, 4-inch model help Apple boost iPhone sales? The rumored "iPhone 5se" is among a number of refreshed products Apple plans to unveil at a March 15 event, according to 9to5Mac.

The 4-inch smartphone is reported to have a slightly upgraded design compared to the iPhone 5S, which launched in 2013. Expected features include an A9 chip, upgraded camera, the Apple Pay mobile payment system and support for Live Photos. However, it's not expected to get some of the cutting-edge features found on the iPhone 6S, such as a pressure-sensitive 3D Touch display. In addition to the smartphone, Apple may also unveil an iPad Air 3 and a new set of Apple Watch straps.

Apple’s 9.7-inch iPad Air 3 is expected to come with a number of upgrades similar to those on the 12.9-inch iPad Pro, such as upgraded built-in speakers, front-facing flash and the addition of a smart connector for external keyboard cover support, according to Engadget. The unveiling of a new Apple Watch had been expected for the March event, but now it’s more likely that a redesigned Apple Watch will debut in September, according to TechCrunch. In lieu of a new Apple Watch, new bands such as a black Milanese Loop, colored sport bands and additional Hermès bands are expected to make an appearance at next month's event.

On the other hand, Apple might launch the products through an online-only announcement, according to 9to5Mac. Beyond the March product announcements, Apple may also be working on a fully revamped smartphone, which could be called the “iPhone 7.” However, the new device isn’t expected to debut until sometime in the second half of 2016. Analysts are hoping the upcoming smartphone will reverse an anticipated year-over-year decline of iPhone sales starting in the quarter ending March 26.

Apple iphone 5se Apple's anticipated 4-inch iPhone 5se is expected to come in a form that resembles an upgraded iPhone 5S. Photo: Reuters/Jason Lee