Just debuted as sequels to Just Mobile's earlier Highway and Highway Pro, the new Highway Duo ($40) and Highway Max ($25) are variations on the original "handsome metal-capped car charger" theme. Both allow you to charge up to two devices at once. Highway Duo features a standard USB port with 1-Amp output, as well as an integrated 2.1A Lightning cable. By comparison, Highway Max has two ports like Highway Pro, but both put out 2.1A. Max includes a…
