An all fiber optical filter is formed by stretching an optical fiber. A washing solution containing a detergent is spurted against the endoscope arranged within the washing vessel for washing the endoscope. Two strips of green rubber may be simultaneously processed and then joined such that the respective layers of conductive coating are in spaced apart opposing relationship. A second GUI is also provided for selecting at least one audio segment corresponding to the entry. A photocatalyst is arranged within the interior space and along the airflow pathway, and the ultraviolet radiation can be emitted onto at least a portion of the surface of the photocatalyst to activate the photocatalyst.