Water Carbon Illuminated Seat Heater Hi/lo/off Round Rocker Switch Opening Size:19mm 40cm Long Wire with a Negative We are the manufacturer of this Carbon fiber single seat heater, as professional seat heaters manufacturer, all of our products provide 3-years quality warranty, you can buy with confidence. The diameter of switch: 2cm Round switch with 3 settings: High (red light), Off and Low (blue light) http://www.amazon.com/gp/product/B00N0BD616 1 seat http://www.amazon.com/gp/product/B00N0BY2TQ 2 seat