A Hold-Out Needle Pistol, or "hold-out needler" is an backup weapon with an especially bad reputation. The most common form is that of a unit worn on the underside of the forearm that is designed to be fired from inside the sleeve by a particular motion of the wrist. Since it is designed to be used entirely covertly (the user never looks like he's going for or holding a gun, it is a favored option of spies, kidnappers and assassins.
Hold-out needlers can be loaded with different types of darts, depending on the user's preference: the normal needler round (2d10 damage), the normal needler anaesthetic round (1d10 + sleep), or a round coated with a fast-acting lethal toxin (1d10 + S25/T3). Attempts have been made to introduce a small, explosive-tipped dart (3d10 damage), but the results have been mixed.
Because of the extremely short range the weapon is normally used at - 5 meters or less normally, 7 meters at most - many makers forego the magnetic coil delivery system and use simple compressed gas/air. Depending on the model, they can hold up to 3 needles.
Because they are so popular with criminals, hold-out needlers are outright banned in many jurisdictions. This also makes them a bit expensive compared to other hold outs.The image is of James Bond's wrist-gun from Moonraker.