The Enviro Ink Remanufactured Savin 4310 (Type 3100D) Toner Bottle are compatible toner cartridges that are manufactured by a third party that is ISO 9001 certified, not by the OEM (Original Equipment Manufacturer). This compatible/remanufactured 4310 printer cartridge is designed to meet or beat OEM standards when it comes to printing quality and longevity. Enviro Ink offers Premium Compatible Savin 4310 (Type 3100D) Toner Cartridges at a significant price savings when compared to the original Savin 4310 (Type 3100D). Put money back into your pocket by purchasing environmentally friendly Toner Cartridges from Enviro Ink! Don't forget, all of our Remanufactured and Compatible Ink and Toner Cartridges come with our 100% Money-Back Satisfaction Guarantee.