Both the Black3 and Green3 use a three piece OTL cantilever that has a Grado specific diamond mounted on a brass bushing. The Green3 are hand selected from Black3 production runs which meet higher test specifications. Approximately 15% of the run usually exhibits these specs and become a Green3.
Grado’s OTL, or optimized transmission line, technology provides an ideal transfer of signal from the surface of the LP to the generator of the system. This technology rejects unwanted resonances and lowers distortion preserving the fundamental and harmonic frequencies of the music. This also helps keep noise generated by the motor system in the cartridge to a minimum.
"the Grado Prestige Green is a cartridge most people will find thoroughly enjoyable for nearly all kinds of music, especially if their system is very slightly laid back. At it's price, it simply can't be beaten! If you have a moderately-priced turntable lurking in your closet, pull it out, get a Grado prestige Green"
-Thom Moon / $ensible Sound magazine