ModsJava
RXB-Kit
Lightweight 16x16 building mod. Also nuclear power!. Free Minecraft Java mod for 1.21.1.
⬇ Download on Modrinth
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
Verified by MCModsHub
- Ships as rxbkit-2.0.5-neoforge-1.21.1.jar — drop this file into the mods folder
- Download size: 14.4 MB
- Download link checked 31 Aug 2026 — working
These come from our own check of the pack file, not from the source page.