45 Lumens per Watt output . Replacement lamp for GU10 halogen lamp. Compact size allows use with most non-fire rated. GU10 downlights and spotlights. Lasts 10 times longer than an equivalent incandescent lamp (10,000 hrs). Not suitable for use in fire rated downlights. Non-Dimmable. If used with occupancy sensors these should be set to a 20 minute minimum.