1. Ultra low noise design 2. Use a USB power plug, can be in PC, NB power sharing 3 ... and down the pitch adjustment3. With button switches4. Use a USB power plug, can be in PC, NB power sharing5. ... Can purchase USB power transformer, suggest to buy 5 V, 1000 MA above ... 54x32x63/40pcs3. loading quantity: 20FT: 11200pcs 40GP: 23200pcs 40HQ: 27200pcs mini USB fan GT-616