So - bought this to connect my Macbook Air via ethernet, USB 3 connection. For whatever reason, the computer steadfastly refuses to see the ethernet connection on the port. It may be because it only wants to see a connection via thunderbolt port, or because the J5 software isn't compatible with Big Sur (there are some on-line notes suggesting there may be some issues), but regardless it ain't doing what it says on the tin! If I get the time I'll drop it back and let PB Tech take a look. Meantime, it's aesthetically pleasing, so there's that.