MGS V: The Phantom Pain How to Unlock the Key Items Guide

The Key Items are also part of the collectibles/awards in Metal Gear Solid V: The Phantom Pain. They are badges which unlock different abilities, items and improvements. To Unlock them you have performed certain actions. Here is the list of Key items and how to unlock them in MGS V: The Phantom Pain. 

How to Unlock the Key Items?
As we mentioned above, you need to perform certain actions and automatically you will receive the key item like an award. They Mainly unlock the abilities and the researchers needed for your Mother Base. You can touch the Key Items and also use it for where ever you want.

Children's Reward:
How to Unlock: During the Mission 18, You need to rescue the children from the Mines. 
Reward: Water Pistol is unlocked for the research.

Master Certificate(Marking):
How to Unlock: You Need to Mark 500+ People/Objects
Reward: Unlocks Enemy decoys

First Aid Manual:
How to Unlock: You need to After Mission 18, Search Masa Village
Reward: Unlocks Fulton Gear for D-Dog

Master Certificate(Fulton):
How to Unlock: You need to You Need to Extract 500+ enemies
Reward: Unlocks Fulton Upgrade Grade 3

Grand Master Certificate(Fulton):
How to Unlock: You need to You Need to Extract 1000+ enemies
Reward: Unlocks F-Ballista for D-Walker

Master Certificate(Box):
How to Unlock: You need to You Need to Collect all Invoices in Afghanistan or Africa
Reward: Unlocks C-Box WR

Grand Master Certificate(Box):
How to Unlock: You need to You Need to Collect all Invoices in Afghanistan and Africa
Reward: Unlocks C-Box SMK

Conch Shell:
How to Unlock: You need to complete Side Op #113 - "Eli's Challenge"
Reward: Unlocks Fulton Upgrade

Skull Machete:
How to Unlock: You need to complete Main Mission #29 - "Metallic Archaea" 
Reward: Unlocks Task-Arm SM for D-Walker

Strangelove’s Memento:
How to Unlock: You need to complete Side Op #143 – "Extract the A.I. Pod" 
Reward: Unlocks Bandana

Man on Fire(Corpse):
How to Unlock: You need to complete Side Op #144 - "Secure the Remains of the Man on Fire"    
Reward: Unlocks Furicorn uniform for D-Horse

Quiet’s Examination Report:
How to Unlock: You need to watch cutscene 'Quiet’s interrogation at Mother Base' or complete Main Mission #40 – "Cloaked in Silence [Extreme]".
Reward: Unlocks Gray XOF uniform for Quiet

Handkerchief:
How to Unlock: You need to complete Main Mission #40 – "Cloaked in Silence [Extreme]".
Reward: Unlocks Sniper Wolf uniform for Quiet

Emmerich’s Research Notes:
How to Unlock: You need to watch the cutscene where 'Emmerch is exiled from Mother Base'.
Reward: Unlocks Stealth Camo Uniform

Master Certificate(Standard):
How to Unlock: You need to complete every main mission with any rank(except the ones on hardest difficulty). 
Reward: Unlocks Cyborg Ninja Costume

Grand Master Certificate(Standard):
How to Unlock: You need to complete every mission with any rank(except the ones on hardest difficulty).
Reward:    Unlocks Raiden Costume

Master Certificate(Elite):
How to Unlock: You need to complete all missions on high difficulty levels(Extreme, Subsistence, Total Stealth with any rank).    
Reward: Unlocks upgrade for Naked(Silver) Costume and Bionic Arm(Silver) 

Grand Master Certificate(Elite):
How to Unlock: You need to Complete all missions on high difficulty levels Extreme, Subsistence and Total Stealth with S Rank    
Reward: Unlocks Naked(Gold) Costume 

Star of Bethlehem:
How to Unlock: You need to Finish the Phantom Pain’s secret Mission #46 – "Truth: The Man Who Sold the World".    
Reward: Unlocks Infinity Bandana

The Codename - 'Big Boss':
How to Unlock: You need to complete the Phantom Pain’s secret Mission #46 – "Truth: The Man Who Sold the World".    
Reward: Unlocks Leather Jacket uniform