Premium 30323 Black on White Standard Shipping Labels (220 pcs) fully compatible with the DYMO LabelWriter 4XL, 320, 330, 330 Turbo, 450, 450 Duo, 450 Turbo, 450 Twin Turbo, EL60, EL60 Turbo, SE300, Twin Turbo. The use of compatible supplies does not void your printer warranty.