The display capacity and nominal capacity are different because the calculation methods are different. Manufacturer standard: 1GB=1,000MB / 1MB=1,000KB. Operation system standard: 1GB=1,024MB / 1MB=1,024KB Use A-class chip, can be erased repeatedly for 100,0000 timesOperating System: Win98/ME/2000/XP/ Vista/win7 /win8, Mac OS 9.X/Linux2.4 or aboveAbout Real Capacity: Please kindly note the memory about the capacity for the storage products Environment Temperature: -40C - +70CStorage Temperature: -50C - +80CUSB Service Voltage: 4.5V-5.5V.syi