This moc has been as a mod to the actual 75571 AMP mecha in order to make a more accurated version from the movie but still respecting the lego color scheme and using most of the pieces from the set. The xml part includes only the extra pieces for the mod so you will need the 75571 set.
The Mitsubishi MK-6 Amplified Mobility Platform (or “AMP” suit) is a distant descendant of the first military exoskeletons used on Earth in the mid-21st century. It was improved during military service in a myriad of combat theaters – from arctic to jungle to desert – over the decades. Sealed and pressurized models for toxic environments were developed as well. The suit is used extensively on the Moon and Mars colonies (where they are powered by fuel cells and/or monopropellant ceramic turbines). Its well-tested capabilities have proved invaluable in the deadly environment of Pandora. The Na’vi name for it roughly translates as “shield that walks” or “not-demon walking”.