Because Apple didn't manufacture their own printers through the years, replacement ink jet tanks/cartridges or toner cartridges can often be found by cross-referencing their models with the equivalent models made by the actual manufacturer. In the case of the Apple LaserWriter Select 300, 310, 360, and 610, you can use a toner cartridge designed for the Xerox 4505, 4505ps, 4510, and 4510ps models. The Xerox toner part number is "113R5," which can be purchased new for $120, whereas refilled toner cartridges can be purchased for less. Keep in mind that even new/sealed toner cartridges have a shelf life, so you don't want to buy one that has been sitting in inventory for a long time. If the printer is working well mechanically, I'd be more inclined to buy a new toner cartridge from a Xerox dealer/supplier.