Switches sense tilt over 360DEG of a vertical axis. A common use is in portable heaters used in the home to prevent electrical shock or fire. When the heater tilts more than a specified angle, the switch operates turning the heater off. This angle, called the operating angle, describes the angle from vertical to the point of contact operation, subject to a tolerance, ie. 45 DEG+-10DEG (35DEGto 55DEG). Both normally closed (tilt to open) and normally open (tilt to close) switches are available