WINGS OVER HOUSTON: An A-10 Thunderbolt II, an F-35 Lightning II, an F-16 Viper and a WW2-era P-51 Mustang fly in formation over Ellington Airport, Houston, Texas. Photo taken Oct. 11, 2020. The F-16V (Viper) is an upgraded version of the F-16 Fighting Falcon. The manufacturing apparently suggested renaming the upgrade the F-21. That designation shows up in reports and analyses, but it hasn’t “entered standard usage,” so to speak.

Quote from the Warplanes update:

The changes in the V model are considerable. The airframe is upgraded and strengthened to enable 12,000 flight hours per aircraft. The electronics undergo an even more extensive upgrade which involves replacing the mechanical radar with an AESA (phased array) radar, an upgraded cockpit, a Sniper targeting pod, a Link 16 digital data link and upgraded navigation gear. The newly redesigned cockpit is all digital and flat screen touch displays that replace dozens of gages and switches and makes it much easier to fly the aircraft.

More data at the update.