It is a special cement powder to which water is added and it turns into a special mixture or mortar for plastering work. This type of powder contains special materials that make it an insulator against heat and moisture because it contains perlite. This product is widely used in areas characterized by high weather temperatures. Buyformula website will teach you the best method for making this type of water proof plastering mortar. Formulas are available in PDF format file, that described in technical English language.