The product is made of high quality cold rolled steel plate. The thicknes of steel plate of filing cabinet is generally 0.6mm before powder spraying ,and we offer an optional 0.5 -1.2mm of cold-pressed steel plate. Inside :3 layer adjustable plate, or custom the number of layers. Adjust the number of layers and the height between layers to fit file size. Outside :The type of lock is optional. The color is optional. The handle is optional. If you have any other questions or requirement, please consult with us.