Fiber Dear Customer, Galaxy M31 comes in a Premium Polycarbonate design. Hope this is of help. Regards, Samsung India Dear Customer, Galaxy M31 comes in a Premium Polycarbonate design. Hope this is of help. Regards, Samsung India Fiber####[['Premium Polycarbonate design', 'Appearance Design#Exterior Design Material', 'neutral'], ['Premium Polycarbonate design', 'Appearance Design#Exterior Design Material', 'neutral']]