The Masterplug LED GU10 Truefit Bulbs have a true halogen appearance and a perfect fit. They use the latest LED technology and provide up to 90% energy saving and 10 times the lifetime compared to halogen bulbs. Non dimmable. Specifications:Switching Cycles: >15,000. Bulb Diameter: 50mm. Bulb Height: 54mm. Input Power: 3 Watt. Lumens of Light: 260 (25 Watt equivalent). Colour Temperature: 6000K, cool white.