The Mandalorian is known for its various Easter eggs and references to other aspects of the Star Wars universe, and "Chapter 15 - The Believer" was a great example of this.
The episode most notably mentions Operation: Cinder, the Emperor's contingency plan from Star Wars: Battlefront II. "The Believer" also references the prequel trilogy, marking the return of the seismic charges from Attack of the Clones.
Several stills from the episode have been released by Star Wars, providing better looks at Migs Mayfeld's return and an unmasked Pedro Pascal as Din Djarin. A poster was also released of Ming-Na Wen's Fennec Shand, who seemingly returned from the dead in "The Tragedy." In the wait between now and the series finale, some Star Wars fans have used clues from "The Believer" to try to pinpoint Moff Gideon's location.
Now, a few more Easter eggs have been uncovered regarding Boba Fett's jetpack...
As found by Twitter user @bobafettfanclub, "Chapter 15 - The Believer" contains a few Easter Eggs related to Boba Fett's jetpack.
Aboard the Slave I, Boba Fett's jetpack from Return of the Jedi can be seen behind Migs Mayfeld. The jetpack possesses the same color scheme and battle damage from Episode VI and is the same one seen in "Chapter 9" and "10" of The Mandalorian.
Boba Fett also has a new jetpack that possesses a color scheme closer to the one he used in The Empire Strikes Back, albeit being much more polished. However, the new jetpack seems to be the exact same shape as the ROTJ jetpack, indicating that the production team used the same mold to create Boba Fett's gear in the show.
WHAT THIS MEANS
From this, it appears that Boba Fett does indeed have two jetpacks, retaining his previous one from The Empire Strikes Back whilst also acquiring his Return of the Jedi pack from Mando in "The Tragedy." It was previously thought that Boba only had the one pack, simply being a polished version of his Episode VI jetpack to match his cleaned-up armor. This new Easter egg seems to contradict this belief, indicating that the bounty hunter kept his prior jetpack aboard the Slave I.
Some fans have speculated another theory, believing that Boba actually used his retrieved jetpack from the Sarlacc Pit to mold a new one. This would explain in-universe why the two have the exact same 'patch' that is featured on the Return of the Jedi pack. This would seem rather quick, however, and it is unknown what sort of tech Boba is working with aboard his ship. Therefore, it is perhaps more likely that Boba Fett simply retained both of his jetpacks, but only ever had one set of armor. With Mando also possessing his own jetpack now, this piece of gear seems to be much easier to come by in the Star Wars galaxy compared to a full suit of Mandalorian armor.
This production 'error' is interesting in that it made it into The Mandalorian and was noticed by fans. The Disney+ series has had its fair share of oversights, but this seems to fall in line with the constraints and subsequent mistakes seen in the franchise ever since the original Star Wars.
Both of Boba Fett's jetpacks can be found in "The Believer," which is streaming now on Disney+.