These Crompton LED T8 4ft 22watt glass tubes provide 2050 lumens of light output and includes an LED starter for direct retrofit into existing single batten fittings. With an energy rating of A+ this cool white 4000k tube is used in many applications ranging from Offices to Kitchens. With a long average rated life of 40,000 hours this bulb is energy saving with low power consumption.When using a switch start magnetic ballast, use the LED starter provided with the lamp. When using an electronic high frequency ballast, bypass the ballast and wire directly to the mains, this task should be carried out by a qualified electrician. Crompton Lamps recommends wiring directly to mains for optimum efficiency. Not suitable for emergency circuits.