What I liked about this unit is that it has a fan and timer. This is a good product with one flaw. The frequency response is an outstanding, 12-35,000 Hz, which is 1,500 Hz short of Hi-Res territory. He absolutely loves it! The GPW is a pricey glimpse into the normative future, and the future looks like a nice place to live if we can avoid asteroids, plagues and nuking ourselves into oblivion (etc. I was afraid that these would not fit because a few reviews on another site said the wide width was too narrow. Although it fits when full and heavy the liquid pulls the cup holder down, spilling said drink. Now I have no problem or pain. Comfofor walking /and I walk a lot! I was so excited when I received these slippers.