Nellik's-HighDef-GUI-4.2.0-1.16 is a release file of the Minecraft resource pack Nellik's GUIs Revamped, made for Minecraft 1.16. It was published on October 14, 2020 and is 4.1 MB in size. For the full description, screenshots and every other version, visit the Nellik's GUIs Revamped resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.