Ambyx's Grapple Cannon

Though conceived from the innocent desire to make something unique, these rare pieces apparatus are already popular with burglars, and are fondly known as a 'Black Arch Exit Strategy' among the less savoury types of Sharn's underworld.

This mechanism incorporates a regular grappling hook attached to a harness by a winch, as well as a foot long metal tube with a simple trigger mechanism. When the trigger is pulled, the grappling hook is launched into the air  with extraordinary force by a magical charge. Once the launcher has been used, it may be reset by spending one minute to calibrate the trigger mechanism and expending a second level spell slot to replenish the charge.