Recently bought this fine small mono laser printer.  Its just started to warn me that the toner is low. Be aware that this type of product comes only with a starter cartridge i.e. not full of toner. Hence the apparently attractive prices on the likes of Ebuyer and Amazon. Still it does a nice job. Mindful of the cost of a  genuine replacement cartridge I’ve gone to my trusted toner refill supplier ‘U Refill Toner Ltd’ . One of the most helpful companies I’ve dealt with. What I’ve now realised is that these new models ‘chip’ the cartridge just like they tend to do on the ink jet machines. Still the refill kits supply a new chip , but obviously this whole process is more expensive as a result. Haven’t changed mine yet, simply added some more toner. U Refill…. conveniently supply a small electric hot melt device to cut a small hole. Great fun , but take care not to get too dirty.