Tactical Vests are an item added by The Crafting Dead which provide more inventory space for the player allowing him or her to carry more items
Tactical vests are equipped by placing them onto your torso by opening the Crafting Dead inventory. The original key to open the inventory is G but you can change that in the control options. After the inventory is opened equip the tactical vest into the bottom slot and you will be granted more space.
Tactical vests function similar to backpacks so when you equip them and you get more space, but carry less items. Unlike what the name would suggest, tactical vests do not provide any protection to the player, and only serve as a way of storing things.
On multiplayer when having a vest equipped, after logging out it may disappear (needs confirmation)
this Has Been Fixed