With just one day to go before Apple makes its iPhone announcement, the purported specifications of the iPhone 5S have leaked online.

Apple is expected to hold a big iPhone event on Sept. 10 and the company has even sent out some colorful invitations to the press conference. As usual with such high-profile unveilings, the rumor mill is churning at full speed ahead of the big event and leaks, rumors and speculations only intensify as it gets closer.

With the iPhone 5S so close to becoming official, the alleged specifications of the smartphone have now leaked online, apparently confirming previous rumors. The latest leak includes some snapshots of what seems to be marketing material for stores and carriers, and comes from CTechCN.

According to the snapshots, the purported iPhone 5S does seem to pack the much-rumored fingerprint sensor, as well as Apple's A7 processor. The next-generation smartphone will likely not boast a bigger screen size, retaining the 4-inch display of the iPhone 5.

The smartphone's home button also seems redesigned as rumored, most likely in order to accommodate the fingerprint sensor technology. The iPhone 5S will also reportedly deliver a better battery performance, offering a new standby time of 250 hours, a notable improvement over the 225 hours its predecessor had to offer.

In terms of camera, the next-generation iPhone will reportedly turn it up a notch to an 8-megapixel rear shooter with dual-LED flash and F2.0 wide aperture lens. The rear camera would also be able to record Full HD video at up to 120 frames per second (fps). A 1.2-megapixel front camera, meanwhile, would allow for self-shots and FaceTime chats.

Apple is also expected to unveil a more affordable iPhone, dubbed the iPhone 5C, at the same Sept. 10 event. The company has not confirmed any of these rumored specifications so far, nor has it acknowledged that it plans to offer a low-cost iPhone. The leaked specifications for the purported iPhone 5S remain unconfirmed as well at this point, so until Apple makes an official announcement it's always better to take rumors with a grain of salt.

With just one day to go until the big event, however, it will all become clear and official soon enough. Stay tuned for Apple's big announcement.