The US421A is a 4-port USB 2.0 Peripheral Switch that allows up to 4 computers to share the use of a single USB peripheral device (such as a printer, scanner, mass storage drive, etc.) on a one-at-a-time basis.
1x 4-Port USB 2.0 Peripheral Switch
1x USB Type-A to USB Type-B Cable (1.8m)
1x User Instructions