The Moyno® Series 4 Annihilator™ Grinder, a twin-shaft solids-reduction unit, incorporates a removable quick-change cutter cartridge. The drive components and cutter cartridge can both be removed from the flange housing as one assembly. This single assembly design allows for quick replacement and minimal downtime. The modular construction allows for only two cutter cartridge assemblies to fit all five grinder model sizes for low replacement cartridge inventory requirements.