Atlona USB Extender over single CAT5/6/7 up to 165ft with 4-port USB hub at the receiving end The Atlona AT-USB50-SR is a USB 1.1 Extender set over a single CAT5, 6 or 7 cables up to 165ft (50m). Atlona USB Extenders are a perfect solution for those who want to extend keyboard, mouse or even clock-in machine further away from the computer.