Muscle Tracer (MT):
The Muscle Tracer (MT) is the precursor to the Armored Core. MTs are the most frequent enemies in the series, aside from other ACs. They come in various varieties, such as mobile gun turrets, powered suits, tank-like quadrupeds, and much more. Some MTs even resemble Armored Cores.

Scimitar MT:

Armored cores: Cored MT Unit (Armored Core)
The full name for a Muscle Tracer that is not mass-produced as a single unit in bulk, Cored MT Units are much more powerful than their counterparts and are built differently. Instead of a single set of parts being used, and different models of the MT being built, an Armored Core is built from several different interchangeable parts, to allow maximum customization by their pilots. Some Armored Cores have also been custom made, and the corporations have not reproduced their parts.

AC Examples:





Armored Core