Apple's spring product debuts Monday will technically remain secret until Apple chief executive Tim Cook unveils the season's new gadgets on stage at company headquarters.
But the rumour mill has been churning out leaks for weeks, and inside sources cited by industry media suggest Apple will present at least two new devices at the event in Cupertino, California.
The first, a smaller iPhone to be called the iPhone SE, is expected to combine the 4-inch (10-centimetre) screen size of the iPhone 5 with some of the features of the iPhone 6, in a new lower-end model.
The second will reportedly be a new version of the iPad Pro, combining processing and hardware capabilities of the top-end iPad Pro in a lightweight, 9.7-inch (24.6 centimetre) screen similar to the iPad Air.
The press invitation to the presentation read "let us loop you in," a cryptic phrase that could refer to Apple's street address at One Infinite Loop. But many Apple watchers suspect it could refer to new bands for the Apple Watch, introduced at the annual event a year ago.
Other possible news could include updates to Apple device software or operating systems.
The live-streamed presentation is scheduled to begin at 10 am Pacific time (1700 GMT).
The event will take place one day before Apple and the Federal Bureau of Investigation (FBI) face off in federal court in Riverside, California.
The court has ordered Apple to hack iPhone security protocols to help the FBI gain access to a phone used by one of the assailants in the San Bernardino terror attack in December.
Cook refused, setting off a legal battle and public debate over data privacy and public security.