The Extron SW4 USB PLUS is specifically engineered for professional audiovisual applications where reliable USB switching is required, such as KVM (Keyboard/Video/Mouse) setups and interactive whiteboard applications. This device acts as an active USB hub, supporting USB 2.0 high-speed communication (up to 480 Mbps) and is fully backward-compatible with all previous USB data rate specifications (low speed and full speed). A key differentiating feature of the SW4 USB Plus model is its unique Host and Peripheral Emulation Mode. This "keep alive" functionality continuously mimics the communication between the host and keyboard/mouse devices within the switcher, eliminating the need for devices to re-enumerate after switching inputs, which significantly enhances system reliability and reduces the chance of failed device communications during operation.

The switcher also provides 5V, 500mA of power to each of its four output ports, allowing it to power a variety of attached peripheral devices. Control options are flexible, including front panel buttons, RS-232 serial control for integration with external control systems, and contact closure. The RS-232 pass-through feature further simplifies integration by allowing serial commands to be processed by the switcher while also being passed through to other connected Extron video switchers. Front panel LEDs offer visual confirmation of port activity and input selection status, and a security lockout feature is included to prevent unauthorized use.