55/300-900 Trapezoidal sheet form; It consists of a total of 4 rolls with 55 mm roll height, 300 mm distance between rolls and 900 mm useful closing width. This form, which can be produced from prepainted galvanized sheet or aluminium materials, is generally preferred as a sublayer in roof coatings due to its 55 mm roll height, and can also be used in single layer roof coating using 1.220 mm rolls.