Amerex fire extinguisher brackets are quality manufactured of steel with a primed and powder coated paint finish. The paint finish assures many years of use and meets the latest U/L salt spray requirements (240 hrs. @ 20% salt solution ASTM B117). For Fire Extinguishers with 4.25" Cylinder Diameter. Amerex fire extinguisher brackets are designed for rugged longevity and for use with Amerex fire extinguishers.