The M-146SG is a complete replacement of the welding knob, internal and external pivot joints for the 3M Versaflo M-Series Welding Shield M-153SG, allowing the faceshield to pivot when raised, lowered or repositioned, and is used with the M-400 Series helmets.The 3M Versaflo M Series Welding Knob and Pivot Kit, M 146SG includes a Pivot Socket Cam, Pivot Spring Clip, Pivot Support Cam, Welding Knob, and Pivot Joint left and right assembly. When installed with the 3M Versaflo M Series Welding Shield M 153SG, it allows the faceshield to pivot when raised, lowered or repositioned, and is used with the M 400 Series helmets.