Doudi,
Swepco is a brand of petrol products primarily sold in the USA, including here at Pelican Parts. Here is the link to Swepco's web site:
http://www.swepcousa.com/lubesite/highperf.htm
The Swepco 201 Gear Lub is a favorite for many 911 drivers with 901/915 gear boxws.
Regards, Bruce