Kwik Mix Masonry Cement (Type-S) - 73 lbsMasonry Cement is combined of finely ground Portland Cement, sand and water to form the binding agent used by Masons. It is categorized in strength characteristics designated by the letter 'N', 'S' or 'M'. Type S is a higher strength Masonry Cement. When mixed with sand, Masonry Cement Type S produces mortar that exceeds ASTM C 270 specification for mortar which requires a minimum average 28 day compressive strength of 1800psi and 75% minimum water