metal fan guard: 1.For computer fan,power supply 2.Material:iron,RoHS 3.Size:30-150mm 4.Color:black or white 40mm Chrome steel fan guard/grills:1.For computer fan,power supply2.Size:30mm to 150mm3.Surface treatment:all kinds colors4.Hardness:meets international standards5.apply for 40*40mm series fan6. The drawing of the fan guard: 40mm Chrome steel fan guard/grills