1.18.1 update is an alpha file of the Minecraft resource pack Glass doors + High FPS, made for Minecraft 1.18.1. It was published on December 13, 2021 and is 4.3 MB in size. Pre-release builds can contain bugs — back up your world before installing. For the full description, screenshots and every other version, visit the Glass doors + High FPS resource pack page.
How to install: Put the .zip into .minecraft/resourcepacks (do not extract it) and enable it under Options → Resource Packs.