CORSA Performance Black PVD Pro - Series tips are dual - walled stainless steel. The dual - wall is designed to protect against heat distortion and maintain visual appeal. Each tip is adorned with high - definition, precision laser engraving that provides unmatched detail. Physical Vapor Deposition (PVD) Technology PVD is a vacuum coating process of vaporizing a solid metal to a plasma of atoms. Vapor is deposited as a high performance reflective coating to create our black stainless steel Pro - Series tips.