A gun concealed inside or in the shape of a briefcase.
Most of the examples under IKEA Weaponry pack away into a briefcase when disassembled, other than those deliberately disguised as something even more innocuous.
Turns out to be a case of Truth in Television. The CIA, as well as American government and military bodyguards, do actually use submachine guns concealed in cases (just like the one [...] [tvtropes.org]