Each of the five Quintet Series cartridges has its own individual sonic expression, and all five models together represent the ensemble of five classic variations:

MC Quintet Mono is a true mono cartridge for playing mono microgroove vinyl records
MC Quintet Red is an all-purpose cartridge that delivers open, dynamic sound with a slight touch of warmth
MC Quintet Blue adds more dynamics and resolution, sounds more open and reproduces more details
MC Quintet Bronze adds even more details and resolution but in a very evenhanded way that pays respect to all elements
MC Quintet Black S is the best of everything, true to the groove with resolution and accurate insight into each recording