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.