Dura-25 increases the flexural, bond, and compressive strength of grouts, masonry and stucco coatings, and masonry mortars. The product improves resistance to oil, water, salt, and chemical penetration, as well as freeze/thaw cycles. It also bonds new-to-old, while exceeding ASTM C1059 Type II requirements for latex bonding agents. US Spec. 800-397-9903. www.usspec.com