Solare Fresnel (array) Silion on glass, strong and shock protected High optical effiency Long life use. Solar fresnel lens(array)Silion on glass, strong and shock protectedSize: 770x520mm, total 24 unit, each unit: 125x125mmFocal: 145mmThickness: 3.2mmOptical effiency: 75% Solar Fresnel lens(array)