Noah Noir ·Studio collection | De-sunglasses。Never been worn - I was sent a different pair and couldn\'t exchange. These are from their high end collection: STUDIO. This collection was named after \"STUDIO\" because of the lenses of its products. They all have gradient lenses, custom-made at our factory, for this particular collection. The sunglasses also have metal endings on the temples. Noah Noir | Round Shape - Frame Color: Black - Lens Color: Gradient Noir Hand Polished Width-Nose Gap-Height Measurements of this pair: 140-23-47 mm Lenses: Base 0° Hinge: Five-barrel Front thickness: 6 mm | Temples\' thickness: 3.5 mm Lenses Technology: ✓ CR-39 Lenses CR-39 is made by polymerization of diethyleneglycol bis allylcarbonate (ADC) in presence of diisopropyl peroxydicarbonate (IPP) initiator. \"CR-39\" is an abbreviation of Columbia Resin 39. CR3-9 has the highest Abbe value of any lens. An Abbe value defines the chromatic aberration of material, and this effect is generally more noticeable in peripheral vision than when looking through the center of a lens. ✓ 100% UV Protection. ✓ Lenses Category: 3. Category 3 in lenses, is considered better than categories 2 & 1. This is because they provide extra protection from both visible and UV light. These lenses allow less than 20% of visible light to penetrate the lens. This means that they will block out 80%+ of light. Category 3 lenses are considered the best lenses in the optical industry. Acetate Technology: ✓ Italian (Mazzucchelli) and Portuguese Raw Materials.