I have been using M cartridges for my P-Touch for years to label anything and everything, including all of those pesky cords and chargers that seem to multiply around the house. We kept ending up with boxes of cords and cables that no one quite knew what they went to, and in many cases they went to devices that had been tossed long ago. By labeling cords when they come in the door, I can better keep track of them and eventually dispose of them without fear of reprisal. The adhesive lasts indefinitely (I haven't had any come loose in the time I have been using the product) and the cartridges dispense correctly every time.