Gundam HG Build Custom HGBC #028 Lightning Back Weapon System MK-III (3) 1/144 Model Kit This is an all-new back weapon system that is being added to the HGBC series! Equip this backpack and enhance your mobile suits! The weapon system can be used to customize a variety of model kits, including existing models! The front end of the backpack can detach to create a wieldable weapon! Enjoy a wide range of weapon combinations.