The Bowers & Wilkins CWM664 are a pair of in-wall speakers for your integrated home audio requirements. CWM664 just below the CWM663s they provide virtually the same level of quality & fidelity as the CWM663s. The main difference is simply the lower amplifier power these speakers have. If you dont require the full 150W of power then these speakers are most likely the best option for you. They still feature the same HF switch to tune the speakers sound to your home.