I have one about three metres long, seems to work fine.
Think its good up to about five metres before some form of amplification is required
Normal ones go up to Five meters before you get signal problems. However you can get "Active" repeater extension leads in both USB2 and USB3 which seem to be offered in much longer lengths. I have never used an active one so do not know how reliable they are. but they seem to have good enough reviews.