A robot that is capable of substantially autonomous movement includes a processing device, a memory, and a mobility structure controlled by the processing device. In one embodiment, a home theater at a subscriber premises includes multiple home theater components, which include multiple audio playback components and a video playback component. The members are two-dimensionally arranged with a period of 400 nm to 500 nm. At least one of a subtank and an adjuster as functional components of the shock absorber is located in the exposing portion.