CableWholesale AB 2 Way Switch Box, DB25 Female Warranty: Lifetime Converts back and forth between DB25 Female Plug and 2 DB25 Parallel Ports AB parallel port switch box is a rotary unit that is used to share DB25 Has parallel D-USB 25 pin female ports and an input/output port with a rotary dial to switch between them 2-way parallel printer switch can used for audio recording equipment and lab microscopes