High-pressure sodium vapor lamps for open and enclosed luminaires. Product features: Lamp survival rate: 95 % after 28,000 h burning time. Lamp maintenance factor: ≥ 80 % after 24,000 h burning time (according to DIN 13201). Dimmable on conventional control gears and electronic control gears. Product benefits: Very long lifetime. Very high luminous efficacy. Extended service time (lamp replacement cycle): 8 years (at approx. 11 h/day). Very good luminous flux maintenance throughout the life of the lamp. Optimum energy efficiency on POWERTRONIC® PTo 3DIM ECGs. Areas of application: Streets. Outdoor lighting. Industrial installations. Suitable for use in open and enclosed luminaires. Outdoor applications only in suitable luminaires. Alternative to sodium twin arc lamps.