... .Durable roofing:50-100years; 3.Multi-colors:Rusty. Rusty Nature slate: Product Name Slate tileFinishingNatural split, back calibrated or notChamfered or notPre-holed ... or notStandard ShapesSquare, Rectangle, U type and Fishing scaleMaterial:Natural slate Optional Colors:Black, Rusty, Green, Yellow Standard Sizes(mm)200x400 ... per 20'C: About 1200SQM (25MT, 6-9mm thick) Rusty Nature slate