Railing: 42 mm Bridge: 24 mm Shank Length: 140 mm Grilamid Raw Material - CR39 Lens Grilamid Natural raw material produced in Switzerland is resistant to impacts and does not break easily thanks to its flexible structure. It is antibacterial and antiallergic. Grilamid Natural raw material is sterile, does not cause bacteria and does not contain Bisphenol A (BPA). It does not harm your health. It is extra light