Amtico Xtra - Slate 18 x 36 Cumbrian Slate: 6.75 S/FT, covers 45.000 per S/FT, contains 1.000 per Box, measures 36.000 Inch long, 18.000 MM wide, 2.500 Inch thick, weighs 30.000 lbs, composed of Vinyl, has a Squares design, Smooth surface type, Beveled edge type, Square end type, has a 15 year warranty