If you've played Metal Gear Solid, you know what it is. If you haven't, this is a new item/ stealth mechanic that gives you a Cardboard Box that can be equipped and will hide your character from enemy detection. Please read the description and differences between the files. You can not use all of them at once. 

INSTALLATION: 

Either install Manually (extract contents of the .zip file into your Fallout 4 Data folder) OR use your mod manager of choice [Recommended]. 
I've installed/unistalled/reinstalled with vortex several times without issues.

DO NOT download and use all three of the files. They're all the same item with different stats to suit your preference. If you want to try them all - install one of the files, try it out in game, uninstall it, Install the next version you want to try, Uninstall it, repeat. 
Please don't install them all at once

To Uninstall, you can manually delete the files (using the contents of the zip folder as a reference), OR by mod manager if you installed through that.

IN GAME:

You can find the box at the exterior of Vault 111, it's in the blue trailer thing next to the vault tech billboard. See images. 

Or you can just console it in-
" help cardboard 0 "
" player.additem [whatever the id number that comes up is] 1 "

- The Big Boss/ Boxhound Version can be crafted at a Chem station, in addition to the Vault 111 exterior location in the picture.

FILE DIFFERENCES: 

NAKED BOX - This file is JUST the Cardboard Box without any benefits to your stealth. I kept this uploaded in case anyone else wants to mess around with it. Or maybe you want to play as an ugly character who doesn't want any npcs to see your face. 

SOLID BOX - This version WILL give you Stealth Benefits. While sneaking and remaining still under the box you won't be noticed by enemies, but once you start moving you'll be more noticeable. The faster and more recklessly you move, the greater chance there is to be detected.
(All effects were added by Thesonburn)

BIG BOSS BOX - This version gives you even GREATER Stealth Benefits. While sneaking under the box, you will not be noticed unless you get right up in an enemy's grill, or fire your weapon. Once you're caught in the CAUTION or DANGER state, the box will be automatically removed, and can't be put back on until you return to the HIDDEN state. This version can also be crafted at a Chem Station.
(Contains a small script, All effects were added by Octodecoy (NOT the Darpa Chief))

Foxhound Box/ "Boxhound: Subsistence" - This is the latest version. This file provides you with a holotape (craftable at a Chem Bench) that allows you to customize the box. You can toggle the entirety of stealth features on/off. You can toggle the movement penalty on/off. You can toggle the automatic unequip when discovered on/off. 
This file is essentially all previous versions in one depending on what you toggle on the holotape. Can be crafted at the chem bench, or found in the same location as the others. 

OH WAIT - Now you can customize the box's patterns at an armor bench! There will be no "real" difference in the stealth stats if you change the design, but if you want a little extra immersion when you're using it in different environments. 


CREDITS:

This would just be the "Naked Box" version without these two S++ Rank Nexus users

thesonburn - Stealth effect skills for the SOLID Box

octodecoy - Stealth effect skills for the BIG BOSS Box, and the Boxhound: Subsistence Box

BlasterMasterCaster - For suggesting the pickup/ equip sound. How did that not occur to me originally?

Ousnius - For Outfit Studio, along with every tutorial on how to use it other people made

Everyone who commented and expressed their excitement when I uploaded the Non-stealth version.

PJSAS - For this flawless box mod for New Vegas https://www.nexusmods.com/newvegas/mods/49796 by PJSAS If you play NV, Get this mod, it's so much fun.

Bethesda, Hideo Kojima himself, the Fox Engine, but NOT Konami.