This tape is specially designed for cement board finishing. It features a pressure sensitive, heavy fiberglass yarn construction for increased joint strength and overall structural integrity, and it is alkali-resistant. Its alkali-resistant qualities guarantee long-term performance in cement board applications. Perfect for high humidity environments like bathrooms and kitchens. ODYN Alkali-Resistant Cement Board Tape is 300 ft. x 2 in. (91.4 m x 51 mm.).