X-Cell (Fallout 4)

X-cell is a very rare consumable item in Fallout 4.

Background
Created before the war as a general performance enhancer, X-cell never got out of the prototype stage, but was widely distributed on the black market.

Characteristics
It appears to be some sort of inhaler, and boosts all SPECIAL attributes by two points for two minutes, but is highly addictive.

Locations

 * Concord Speakeasy, two may be found in an upstairs bedroom, next to the bed with the skeleton lying on it.
 * Fens Street sewer, in the first room, across the water, tucked behind a grey pipe and a blue pipe.
 * Harbormaster hotel, on the roof, under the counter of the bar.
 * Diamond City, sold at Diamond City Surplus and Solomon's Chem-I-Care (both rare).
 * Goodneighbor, rarely sold at Daisy's Discounts.
 * Railroad HQ, rarely sold by Doctor Carrington.
 * The Prydwen, rarely sold by Knight-Captain Cade.
 * Natick Banks, found upstairs on a table in the diner after the deathclaw fight, sometimes near a super mutant corpse.
 * Vault 88, in the store at the end of the northeast section. Found by going up a dead-end staircase and looking right, it is behind the head of a partially-buried statue wearing a sea captain's hat.
 * Fun House - In the room with a house turned every-which way, look up in the bathroom and jump toward the mirror, it'll be a split second so you'll have to be quick.
 * Nuka-Cade, prize level 5 for 3,000 Nuka-Cade tickets (items rotate every couple of days).

Behind the scenes
X-cell is play on words of the word "excel."