◆ Made of borosilicate glass
◆ Refractive index : 1.474
◆ Abbe number : 65
◆ Thermal expansivity : (3.3士0.1)×10-6/K
◆ Light transimittance (2mm) : 92%
◆ Density (20 ℃) : 2.23gcm – 1
◆ Heat resistant : working at -50~550 ℃
◆ High hardness
◆ Never get yellow comparing with PMMA material
diameter : 78mm
suitable for led size : not bigger than 38*50mm