MicroSHIFT is a Taiwanese component company that manufactures cassettes, shifters, and derailleurs, front and rear. They offer specialized components for road and mountain bikes, as well as a set of drivetrain peices for your city cruiser. With distributors all over the world, they are becoming a decent affordable option for your drivetrain. 

No.1313-6 Zhongshan Rd.
Shengang , CH
24° 8' 50.748" N, 120° 29' 21.8076" E
Chang-hua TW