High Performance, High Efficency and Attractive.When it comes to transferring electrical energy efficiently into air energy for cooling, air recirculation or air movement, J&D Manufacturing is the world leader.We carry Diamond Brite portable drum fans that are available in the following sizes 20", 24", 30", 36", 42", 48"Patented heavy duty Aluminum Diamond BriteTM housings. Heavy gauge corrosion resistant, powder coated wire fan guards meet OSHA 1910.212(a)(5) requirements Motor is totally enclosed, maintenance free, high efficiency, UL and CUL certifications.