Grappling Hook Launcher (3.5e Equipment)
From D&D Wiki
This device looks like a crossbow with a thick stock and no prod (bow part). It uses a strong internal spring to launch a grappling hook long distances. The hook is attached to a rope that is mounted underneath the stock, that uncoils when fired.
To use it you must make a ranged attack, just like a crossbow. The DC is simply a touch attack for a stationary object, which is DC 4. It is very easy to use. (Of course, it might be fun to shoot something that isn't stationary. heh)
The Launcher makes a loud kaPWING sound that is easy to hear. Listen DC -5