... and solid mecury,high efficiency,friendly environmental,long lifetime; fluorecent lamp fixture Power: HE series:4w,6w,8w,13w,14w,21w ... >99%),low THD(<10%) 4.Use tri-phosphor powder fluorescent lamp,more brightness,high efficiency 5.No noise,no flicker,low ... mounting, series connection Application: House lighting, shopping mall,refrigeratory,show case,hotel,office etc