The Metal Door Consists of a Narrow Frame (Rectangle), InSide Which A Design is Made, Which Gives the Door Stiffness. Offten Thues the Slats Located Crosswise. The Empty Space is Filled with SoundProofing Or Heat -shielding Material. A Whole Or WelDed Metal SHEELD FROM THE OUTSIDE, Which PerFORMS A Protective Function. IT All Depends on What Purpose The Doors Will Be Used, T. To. If the Hall is Rented for Training, The Metal Sheet Shoup Be Very Strong To Increase Protective Functions in Avoid Light Penetration Inward.