This retrofit 4ft LED T8 tube light bulb from Crompton Lamps replaces the mercury and other hazardous materials found in fluorescent tubes with modern LED components, making it a much safer, more reliable and more efficient alternative.The tubes linear circuit board is adorned with a series of SMD LED chips that sit within a protective, cylindrical glass shell. This use of glass - rather than plastic - prevents the tube from bending, warping or discolouring over time. Each tube carries a 2-year Lightbulbs Direct warranty as standard, alongside a 5-year manufacturer's warranty.Where a traditional fluorescent tube would use approximately 36W to produce 2310 lumens, these modern LED T8 tubes use just 22W. This, coupled with the light bulbs vastly superior nominal lifetime of 40,000 hours, has the potential to reduce lighting bills by up to 90%. Despite the much-improved performance offered by its LED componentry, it shares the same G13 fitting as the fluorescent tubes its been designed to