SL-SF09 Polarization Axis Position Tester Professional instrument for measuring axial deviation of polarized lenses in sunglasses, specifically designed for motor vehicle drivers' eyewear testing. Product Overview The SL-SF09 Polarization Axis Position Tester complies with standards GB10810.3 and QB2659-2004 for testing polarization direction in polarizing lenses. This precision instrument measures axial deviation with exceptional accuracy for quality control applications.