1) ND: 1.499 2) Diameter: 70mm 3) Seg.: 28mm 4) Base: 200B, 400B, 600B, 800B 5) ADD: +1.00 to +3.00 Features:1) ND: 1.4992) Diameter: 70mm 3) Seg.: 28mm4) Base: 200B, 400B, 600B, 800B5) ADD: +1.00 to +3.006) Central thickness: 7.0-8.9mmTypes:1) Semi-finished ST28 bifocal lenses2) Semi-finished ST28, ST25 and ST32 blended lenses3) Semi-finished ST28 and ST24 round top bifocal lenses