30 Rolls Internet Postage w/Delivery Confirmation Labels Dymo 30387 Compatible for DYMO LabelWriters 330 400 450 Twin Turbo Duo 4XL Printer 30 Rolls | 100 labels per roll | 1 inch core Compatible with DYMO 30387 Internet Postage w/Delivery Confirmation Labels | Dimensions: 2.3" x 10" High Quality, Bright, White Direct Thermal Paper Strong Adhesive | Water Resistant | Color: White