RX-133 "Halcyone"

RX - 133-1 is a mobile-suit created to undergo the development of GM III by Anaheim Electronics. It's original intention was just to adapt the RX-178 Gundam Mk.II's movable frame and its hydraulics to GM II for better performance, not to create a new breed of mobile-suit. Sooner or later, the the test went into a halt due to the irregularity among the RX-178's hydraulics compatibility on GM II frame, if done further instead of cost down it would've created just another over-costing machine. Instead the Anaheim Electronics decided to test the existing data on the Konpeito Arsenal's RX-122 TR-1 Hazel, creating a new proto-type RX frame.

After few system runs and testing, the RX - 133-1 was shipped off to the A.T.T(A.E.U.G Test Team), or 306th Mechandized Fleet's crew. Since from this point the Mobile-Suit practically had no use for Anaheim Electronics, but once and for all to decorate another page in MS history.

On U.C 0087 on the 2nd Battle of Jaburo, RX - 133-1 was deployed for the first time,and later modded into RX - 133-2 for Space Usage.

By U.C 0088 February, among end of the Gryps Conflict the mobile-suit became missing.