Amazon.com: COMMFRONT Industrial USB Isolator, USB 2.0 5000Vrms Isolation (per UL 1577), Low and Full Speed Data Rate: 1.5Mbps and 12Mbps, Plug-n-Play, No Drivers Required : Electronics
Optically Isolated 7-Port USB Hub with SeaLATCH USB Ports - Sealevel
USB TO RS232/RS422/RS485 ADAPTERS W/OPTICAL ISOLATION (FULL SPEED) — Connective Peripherals - Global Store
USB to Optical Adapter Industrial Isolated RS-232/422/485 - Coolgear
Hifimediy USB Isolators - Made for audio to prevent ground loops