The present invention relates to an optical film that is excellent in optical properties and can be produced at low cost. The channel displayed in each television can be individually tuned. Stateful subscriptions may refer to one or more message histories and may include more complex expressions. Information from the plurality of end point detection probes is collected and evaluated to determine removal rate of the layer. During operation of the mobile cleaning apparatus, incoming fluid, typically water, flows through an inlet and is directed through the water jacket and then the radiator for heating.