Binders are technological instruments that provide extra control for the AMBAC systems. The idea is simple: "If four limbs can manoeuvre the unit better than none, why not equip them with 5 or more?" The resulting advancement is the tail binder. First equipped on MSN-00100 Hyaku Shiki, the tail binder was originally used as part of the interface for the testing of the concept of transformable mobile units (the type installed on the Hyaku Shiki is not technologically advanced enough for it to be able to transform, however). The tail binder ultimately served as the fifth limb and demonstrated the usefulness of the concept. The unit performed well against more conventional mobile suits and showed superiority in manoeuvrability. Anaheim Electronics had since then installed tail binders on most of the mobile suits of the same series under Project Zeta, most notably the MSZ-006 Zeta Gundam.
A cousin to the tail binder is the wing binder, equipped on most transformable mobile suits with waverider mode as wings. The system made use of the wings' mobility for the transformation during mobile suit mode as AMBAC limbs and further increasing the number of limbs for the AMBAC system. The tail binder is also seen on later models of military aircraft and space fighters in U.C.0088, on the FF-08 Wyvern.
