Is this just for when the printer says the cartridge is empty but you know there's still some toner left?
Also, would the same key work for the high capacity TN-247 cartridges?
Yes. It is to use all toner in cartridge or to refill the cartridge. It should fit also TN247
@JanisSilis_683591 That's great, thanks! My low toner warning popped up a couple of days ago so it's super timing that you published this model only days before that, hehehe! I've ordered a new TN247 to replace the one in my printer so I'll be ready when the toner is genuinely empty. I can't use the tool until the printer refuses to print, and then I'll report back when I know how many more good pages I get from the old cartridge after using the tool :o)