Inside Parts are a non-essential part of an Armored Core seen from Armored Core 2 until Armored Core: Last Raven and are stored within the "shoulder" of an AC.
An internal compartment from which a variety of devices can be released, including bombs, mines, decoys and radar-jammers. In Armored Core 3 small rockets and napalm rockets were added to the selection. These rockets have no aiming trajectory in the HUD and needed to be fired blindly. Most parts were designed with secondary roles in mind, with a few exceptions, such as the the orbit cannon inside part seen in Another Age. These parts were located in the top rear of the core facing backwards in the Armored Core 2 series and in the shoulders facing forwards from Armored Core 3 onward. Inside parts are no longer present as they have been removed in Armored Core 4.