Falcon Heavy Extended Fairing

From the new Falcon Users Guide: 5.2 x 18.7m. The standard fairing is 5.2 x 13.1m.

Required for National Security Space Launch (NSSL) the extended fairing would mainly be used for the big DoD spy satellites. It'll also be used for very long NASA payloads, such as launching the Lunar Gateway's Power & Propulsion Element already attached to the HALO habitat, rather than launching them separately.

Falcon 9/Falcon Heavy vehicle height

Standard: 70m
Extended: 75.2m

"SpaceX can also provide an extended fairing as a nonstandard service. The extended fairing has the same diameter as the standard faring (5.2 m, 17.2 ft) and an overall height of 18.7 m (61.25 ft)."

From the User Guide

Falcon extended fairing-2021-08_88.jpg

and an official rendered image of Falcon Heavy Extended on LC-39A with the new vertical integration tower for NSSL (being built).

LC-39A DoD upgrades.jpg