Signal and power isolator for USB 2.0 devices, based on ADuM3160 from Analog Devices.
The bus speed is fixed at full-speed and the maximum throughput is 12 MBit/s. This is the limit of the integrated circuit used in this board.
Physically the PCB is dimesioned as a square of 44 x 44 mm and the proper cut outs and mounting holes are added, so the board fits exactly into the enclosure 1551STBU by Hammond Manufacturing, which is a very nice transparent blue ABS project box, measuring 50 x 50 x 15 mm.
This project is a redesign of the board by Tom Keddie, but I could not find a fitting housing for his board on Tindie (https://www.tindie.com/products/TomKeddie/usb-isolator-pcb-only/?pt=ac_prod_search).