Airsoft blend high level of O2 & H2O results in outstanding comfort & healthier eyes. We are using unique silicon material that allows both high oxygen permeability & water content resulting in excellent comfort for extended hours of wear, reducing dry eyes & redness. Specification: Material: Filcon 1 Manufacturing process: Fully cast moulded Water content: 47% Base curve: 8.5mm Diameter: 14.00mm Power range: -0.50 to -10.00 (0.50 steps after -6.00) +0.50 to +8.00 (0.50 steps after +4.00) Replacement: monthly. 1 Box (3 pair).