Very high luminous efficacy. Very good luminous flux maintenance over the entire service life of the lamp. Up to 50 % energy savings when replacing mercury vapour lamps (HQL). Optimum energy efficiency with POWERTRONIC® PTo 3DIM ECGs. Areas of application: Streets, outdoor lighting, industrial installations. Suitable for use in open and closed luminaires. Outdoor applications only in suitable luminaires. Product features: Lamp survival factor: 95 % after 16,000 h burning time. Lamp maintenance factor: ≥ 80 % after 16,000 h burning time (according to DIN 13201). Operating life: 4 years (at approx. 11 h/day). Dimmable on conventional ballasts and electronic ballasts.