Now even the heaviest packages can withstand rough handling. Our Scotch Heavy Duty Shipping Packaging Tape holds strong on all box types, including 100% recycled boxes. It’s even guaranteed to stay sealed. The strong, tough, solvent-free hot melt adhesive locks in your heavy duty contents and locks out everything else. Meets US Postal Regulations for standard packages. Grade: Heavy-Duty; Core Size: 3″; Dispenser Included: No; Adhesive Material: Hot Melt Synthetic Rubber.