◆ Coaxial parallel light principle ◆ 6 different apertures with red-free filter & blue filter they can be switched ◆ 29 kinds of adjustable corrective lenses ,Range of lenses： -35D~+40D ◆ Supplied by 2XAA alkaline batteries (not included) ◆ Deluxe LCD screen handle can be adjustable the brightness of light source ◆ CRl≥90%, ensure to insure real color rengition. ◆ Constant current IC circuit, maintain the optimal lighting effect ◆ Low power consumption led bulb, long life of 20000 h