The MSA Ultra Elite Mask with HUD/Voice Projection Unit is a top-of-the-line respirator mask designed for full facial coverage. With its sleek design and advanced features, this mask offers superior protection and comfort for users in various industrial settings. The MSA brand is known for its quality and reliability, making the Ultra Elite model a trusted choice for those in need of personal protective equipment. The addition of the HUD/Voice Projection Unit enhances the functionality of the mask, providing users with real-time data and communication options for added convenience. Can be used for SCBA or converted to a 40mm gas mask by unscrewing the adaptor. Has a working VPU and a HUD, but I haven’t tested the HUD. I’d imagine it works fine like everything else with the mask.