Heater Bulbs - Replacement 500 to 2000 watt infrared heater bulb tubes Phillips gold equivalent or ruby R7 R7S push fit and SK15 wired connection. Included are bulb tubes for most common 230 Volt and 110 Volt domestic and workplace commercial heaters including the 500, 1.2 - 1.3 and 1.4 - 1.5 R7 / R7S and the 1.5 - 2 kW SK15 infrared heaters including these manufactured by Tansun, Heatmaster, Electrovision and many others.