... <10% 4.High quality balalst, 30000hr ceiling light fixtureCeiling light fixture Power: 2*14w,2*28w,2*35w ... ,2*54wCeiling light fixture Features:1.Material:Aluminium body with reflector ... THD(<10%)4.Use tri-phosphor powder fluorescent lamp,more brightness,high efficiency5.No noise,no flicker ... lighting, shopping mall,refrigeratory,show case,hotel,office etc ceiling light fixture (2*28w)