This noise filter can be used between a PC and USB devices, in an empty USB port, or in series with this product. This is a one-owner item, purchased new. I'm selling two of them as a set because I no longer need them due to a change in equipment. - Box included - Operation confirmed by inserting between PC and USB mouse/keyboard - No smoking, no pets - Packed and ready to ship * Search keywords audioquest audioquest fmj full metal jacket