Chronoboon Displacer

Chronoboon Displacer is a consumable item that is unique to Classic. The item allows players to "save" their active world buffs and re-apply them at another time of their choosing. However, the player cannot be affected by any world buff that they currently have saved.

Though not a part of the original game, this consumable was introduced to allow players to continue playing their characters even after acquiring world buffs for raiding, rather than logging out of them to preserve their world buffs often for days at a time. The consumable offers additional perks, including avoiding a loss of world buffs early outside of the raid (either to unintended deaths in the world or dispels from enemy players), and lets players save their buffs for more difficult bosses rather than having them decay on trash mobs or disappear on learning attempts.

Source
Chronoboon Displacer is sold for by Chromie in Western Plaguelands. In order to purchase from Chromie, the player must have completed the quests A Matter of Time and Counting Out Time (1).

Functionality
When a player uses a Chronoboon Displacer it immediately consumes all of their active world buffs, storing them in the transformed Supercharged Chronoboon Displacer. The player can then use the Supercharged item, consuming it to re-apply these stored buffs at any desired time. These buffs will be re-applied at the same duration they were stored at (if Warchief's Blessing had 45 minutes remaining when stored, it will have 45 minutes remaining when the player uses the Supercharged displacer).

The Superchaged Chronoboon Displacer is unique and bound to the player. A buff will display on the character while they possess a Superchaged displacer, showing a list of buffs being "preserved" and their duration, and informing the player that they cannot be affected by those world buffs that are currently held within that displacer. This prevents the item from being used as a "back-up" buff set, as world buffs are meant to disappear upon dying, giving them a high risk to match their substantial power.

Dragonslaying

 * Rallying Cry of the Dragonslayer
 * Warchief's Blessing

Felwood

 * Songflower Serenade

Darkmoon Faire

 * Sayge's Fortunes (any)

Zul'Gurub

 * Spirit of Zandalar

Unaffected buffs
The following buffs cannot be stored with the Chronoboon Displacer:
 * Any crafted consumable buff (ex. Elemental Sharpening Stone, Flask of Supreme Power)
 * Any player cast buff (Soulstone)
 * Blasted Lands consumable buffs (ex. Gizzard Gum)
 * The Zanza potion buffs (Sheen of Zanza, Spirit of Zanza, Swiftness of Zanza)
 * The Silithus world buff Traces of Silithyst
 * World Event buffs (ex. Fire Festival Fury, Invocation of the Wickerman) or consumable buffs (Very Berry Cream)