two types: systema turbo
http://www.airsoftgi.com/product_inf...oducts_id=1843
"For those of you who seek for ultra-high rate of fire performance, Systema has the answer, with the release of this TURBO motor which delivers 30 revolutions per second (which far surpasses the current performance of the Marui EG1000)."
systema magnum
http://www.airsoftgi.com/product_inf...oducts_id=1842
"In the past, super high speed and ultra high torque were complimentary features that you could not find in a single motor. You could either get a high speed motor, or a high torque motor. Recognizing a major need for a motor that could provide both, Systema embarked on a year long design that finally brings both these features in one package. Employing a break-through design, the new motor, called the MAGNUM, will be equally at home in high-speed or high-torque setup, while beating the performance of all previous generation motors - even those specifically tuned for high-torque or high-speed applications.
Each has 3 different lengths: short, medium, long
This page at the bottom lists some systema motors
even the old discontinued ones. http://www.redwolfairsoft.com/redwol...ceSearchResult
use "systema motor" as search term for that site