I am in need of an extension cable for my iMacs stock USB keyboard. Due to I'll health, I plan on keeping out of my chair for a while and using the keyboard on a table whilst I recline on my sofa. I know all about BT etc. But this seems to be a cheaper and equally effective option. Did some research, but got no conclusive answer....My main concern is that the inline booster will cause logic board damage by putting current INTO the USB port. Any thoughts?