1. Ultra low noise design 2. Use a USB power plug, can be in PC, NB power sharing 3. Air volume and comfortable, close to use, specifications:1. Ultra low noise design 2. Up 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 of transformer6. Personalized colour multiple ...