1. 1.59 polycarbonate photo Lens 2.refelective index: 1.59 3.ABBE VALUE:30 4. up to 40% thinner,33% lighter 5. HC, HMC, HCT 1. 1.59 Polycarbonate photo Lens2.refelective index: 1.593.ABBE VALUE:304. up to 40% thinner,33% lighter5. HC, HMC, HCT also make6.CE certification