
UPDATE: Newly released stills of the bracelets from Fantastic Four: First Steps give us a better idea of what these mysterious bracelets really do.
The freshly teased Marvel Legends Fantastic Four: First Steps figures may include a significant MCU callback to Avengers: Endgame and Spider-Man: Across The Spider-Verse. A bracelet found on these Legends figures could explain how exactly the Fantastic Four will end up in the main MCU.
Send up the Fantastic-Flare! Marvel’s First Family is making its way to the big screen yet again. But this time, Reed Richards, Sue Storm, Johnny Storm, and Ben Grimm are a part of the MCU and its vast Multiverse. First Steps releases in theaters on July 25, 2025.
Hasbro Offers Look at Mystery Fantastic Four: First Steps Costume Detail

To help celebrate Friday, April 4 (otherwise known to Marvel fans as 4-4 day), Hasbro's official social media accounts shared a teaser for the upcoming Marvel Legends action figures for Marvel Studios' The Fantastic Four: First Steps.
The image does not unveil the complete figures. Instead, the Fantastic Four (FF) participate in a team huddle, with their hands reaching to meet in the middle.
Something might stand out to eagle-eyed fans, though. If one looks closely, they'll see mysterious silver wristbands on the Reed and Sue figures.

The bracelet-like devices could be a decorative part of the FF uniform. Ben and Johnny don't look to be wearing them in Hasbro's photo, but none of the Four wear matching uniforms in the movie.
They could also be a new invention dreamt up by the ever-brainy Reed Richards, one that serves a yet-to-be-revealed purpose.
UPDATE: Two new photos from EW have revealed our best look yet at these mysterious bracelets.

Up until now, only Reed and Sue have been seen wearing these bracelets, but this new image also shows Johnny Storm wearing this band. This would contradict a popular fan theory that these were wedding bands for Reed and Sue.
Also, interestingly, both Johnny and Sue wear these bands outside their spacesuits, meaning they aren't related to the functions of their spacesuits.

After a closer examination of the bracelets, it seems likely that they are communication devices between all the Fantastic Four members or a device that controls functions inside the Fantastic Four's headquarters, the Baxter Building.
Could the Fantastic Four's Wrist Bands Have MCU Connections?

Perhaps the FF's wristbands hold deeper importance. They may even present a connection to other popular Marvel movies.
MCU devotees might recall that in 2019's Avengers: Endgame, Tony Stark whipped up a sort of time-space GPS to help Earth's Mightiest Heroes navigate the Quantum Realm and travel to the past. These devices were small silver bands but worn higher on the hand, over the palm.
Additionally, in the 2023 smash hit Spider-Man: Across the Spider-Verse (produced by Sony Pictures and not a part of the MCU), the Spider-Society utilizes so-called Multiversal Gizmos to navigate different universes and planes of reality. The Gizmos serve a similar function to that of Tony Stark's creation.

It seems possible that the Richards built wristbands for the entire Fantastic Four to navigate the Multiverse. This feels especially likely when considering that Reed has apparently done research into other universes in First Steps.
Whatever the intention behind these wristbands in The Fantastic Four: First Steps, whether Multiversal in nature or not, one must admit they do stand out.
And while the Avengers themselves won't cameo in the film, they have been confirmed to team up with the Fantastic Four in 2026's Avengers: Doomsday.
If Marvel indeed wants to draw attention to the gadgets, it must be for a good reason—a reason that audiences will need to wait to discover.