When the Speed Force manifestation of Snart attacks Jay, he comments, "Getting a little slow in your Golden Age, Garrick!" This is a reference to the fact that Jay Garrick is known as the Flash of the Golden Age. He was a member of the Justice Society of America, the precursor of the Justice League.
Marks the first time that director Gregory Smith has directed an episode of The Flash. He previously directed episodes of Arrow and Legends of Tomorrow!
When Cisco says "To infinity and beyond", he is quoting Buzz Lightyear's catchphrase in the Toy Story franchise.
This episode features 5 speedsters, more than any other episode of the series: Barry Allen/The Flash/Savitar, Wally West/Kid Flash, Jesse Wells/Jesse Quick, Jay Garrick/The Flash and Hunter Zolomon/Black Flash.