A staple knocker is a

tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates b ...

resembling a

screwdriver A screwdriver is a tool, manual or powered, used for turning screws. A typical simple screwdriver has a handle and a shaft, ending in a tip the user puts into the screw head before turning the handle. This form of the screwdriver has been repla ...

, used for removing staples and shredded material. It is called a ''knocker'' because a hammer can be used to hit the end of it and remove long lines of shorter staples.

See also