2011 High Pressure Sodium Lamp 1,Long life span:10000h; 2,High luminous efficacy; 3,Excellent maintenance. 2011 new metal halide Feature:1,High efficiency, long ... ) Brightness degradation: 3% - 5%/1kh 5) Life time:40,000-50,000 hours 6) Full range of colors: cool white(6000 ...