This pack of four genuine Samsung Colour/ Black Toner Cartridges contain everything you need for quality and reliability in your prints from the Samsung CLP-310 or CLP-315 laser printer. When a colour toner indicator flashes red on the printer's display, the corresponding toner is running low. Order a replacement and install it when you see a solid red light. Each colour cartridge features a yield of up to 1,000 pages, while the black cartridge has a yield of 1,500 pages.