This is a foam vent plug for the WASAE Center. Occasionally, the combination of WASAE Center ’s proximity to a shelf or a rear wall can reinforce the WASAE Center's vent energy and cause undesirable nonlinearities in the low frequencies. Wilson Audio’s engineers have provided a tool for these types of installations. WASAE Center is shipped with a Vent Plug installed. If the bass sounds integrated with the rest of the tonal spectrum, features dynamic authority and transient speed in the mid-bass, then there is little need to experiment with the Vent Plug. However, if the bass sounds unnatural or slow, these are symptoms that removing the Vent Plug may be advantageous in the installed environment. Use the process experiment in the owners manual to safely install the vent plug.