Feather boa
From Wookieepedia, the Star Wars wiki.
A feather boa was a device that could be used to strangle sentient lifeforms. It was not known if this was its primary purpose, however.
At some point during his smuggling career, Roark Garnet was imprisoned. The cell's other occupants were a guard who was assigned to keep an eye on him and a droid named M-3PO. Because he was restrained, Garnet instructed M-3PO to smother the guard with a feather boa. Though the droid protested the use of such a device to "attack" a sentient being, he relented and proceeded to perform the task, which was ultimately foiled by M-3PO's politeness.
[edit] Behind the scenes
A feather boa is, of course, a fashion accessory worn about the neck like a scarf, but this is not mentioned specifically in literature.
