The MAC address of VisualTarget enclosures can be found by looking at the list of connected devices from the network switch.
Look for MAC addresses starting with the following O.U.I. (first 6 characters):
00:E0:4A (Ex: 00:E0:4A:12:34:56)
00:E0:4C (Ex: 00:E0:4C:12:34:56)
00:E0:4D (Ex: 00:E0:4D:12:34:56)
The actual MAC address is based on when the enclosures was manufactured. So all enclosures purchased at the same time should have the same format.
As of the time of this writing the MAC addresses starts with 00:E0:4D