The Grapple Gun is a line cable firing device used to assist Batman in his transportation needs. By firing a cabled hook onto a building he can ascend and scale the various buildings or swing from them across Gotham City. It is also used by him as a tool to catch objects and draw them closer or reach them. A larger scaled version is mounted underneath the Batmobile. Both Robin and Batgirl are also seen using grapple guns in their crime-fighting efforts.
The rope is resistant enough to support Batman's weight even from large distances and also two or three people hanging from it. The trigger that fires the rope is also used to reel the rope back by keeping it pressed.
A special feature of Batman's grapple gun was the electric cord that can be activated to bust metallic doors open.
Although the grapple gun was the device of choice to swing between buildings, Batman also used a regular Batrope, which was the basic version of a rope attached to a batarang at the end. This device was mostly used during close combat to stop criminals from escaping.