Kramer Electronics VS-4X4FW VS-4x4FW is a high performance bi-directional switcher for 6-pin FireWire (IEEE 1394) signals. It connects any one of 4 inputs to any one of four outputs. Mechanical (Passive) Switching - No power required. Transfer Rates - 100, 200, and 400Mbps. Desktop Size - Compact size. Two units can be rack mounted side-by-side in a 1U rack space with the optional RK-81 adapter.