Powder coated and proven MIG welded steel construction with catch pin to keep bracket from vibrating open. The catch pin is secured to the bracket with a black rubber tether. Pin must be pulled prior to extinguisher removal.VB9 is for large diameter cylinders up to 8” Bracket is 17 1?2” Tall 8 1?4” Wide & 8”deep with an extra brace to support tall cylinders plus heavier 1?2” adjustment rod.