Samsung CLP 510 Smart chip. These Samsung CLP 510 toner cartridges have a "chip" which enables the printer to read the toner level left in the cartridge. When the cartridge empties and you refill it with this refill kit, the "chip" will still sense that the cartridge is empty. The solution is to replace the smart chip inside the cartridge. You can expect the same amount of printed pages as with an original high capacity cartridge (7000 page yield black and 5000 page yield each color).