Flak

 is a former slaver from Paradise Falls who now lives in Rivet City with his partner Shrapnel. Together they run the Flak & Shrapnel weapons store in the Marketplace.

He is one of the targets for enslavement that Eulogy put a special bounty on. According to Paradise Falls' gatekeeper, Flak sold the slavers out to Rivet City in order to gain shelter there. Before enslaving him, Flak is unkillable. This ensures that there will always be at least one live target for Strictly Business.

Flak and Shrapnel share their store's inventory, so buying or selling from either one of them will update both of their stocks. This means that if Flak is enslaved by the player for Paradise Falls, Flak and Shrapnel's store will still be open. They consistently have a larger amount of caps than the other shops in Rivet City, making them prime sources of cash in exchange for unneeded loot.

Apperances
 only appears in Fallout 3.

Glitch / Exploit
Here you can "take" the item to your inventory without alarming any residents or guards. You will still lose karma. One drawback is you will not be able to sell these stolen items back to the same shop, but you can easily take it over to someone else for some easy Bottle caps.
 * You cannot steal any of the weapons from Flak & Shrapnel's display or shop table, but, you can grab any of the items, walk away and carry them away from the shop into a corner where they cannot see.