We have more leaks of those matching white suits that we saw Thor and Rocket wearing on leaked merchandise. Now we have an even better look at them, along with seeing most of the other Avengers wearing them too.
https://www.instagram.com/p/BqAfXv5jJcJ/?utm_source=ig_embed
https://www.instagram.com/p/BqAUy7bnhMu/?utm_source=ig_share_sheet&igshid=1j6syoebkfftj
As we’ve previously theorized, we believe that these suits will be used to traverse the Quantum Realm as Hank Pym did in Ant-Man and the Wasp. In fact, initial concept art for Hank Pym’s Quantum Realm suit (as shown in the header) look remarkably similar to these leaks.
Additionally, now that we have a closer look, they’re all fitted with some sort of device on the back of their hand which looks exactly like the device found on Ant-Man of those Avengers 4 set leaks.

Image Provided by JustJared
Another idea is that these devices are what are actually holding the Quantum Realm suits, much like how Tony’s chest piece in Avengers: Infinity War was holding his suit using nanotechnology. It would explain why Paul Rudd is wearing his full Ant-Man suit on set above, yet is covered in dots, as if something is meant to cover it in post-production. It would also explain why Iron Man is seemingly wearing the Quantum Realm suit over his armor in these leaks.
Whatever the case, that Avengers 4 trailer can’t come soon enough.
Source: Instagram (@kpow_ok / @geekevreni)