Optical power in Water: +13 dioptres Aluminum body (6082) Hard anodized coated 40 microns Two flat glass BK7 with anti scratch and anti-glare 4 elements, 3 groups Compatible cameras: Optimized for sensor sizes 36 mm x 24 mm (135 mm full frame) Magnification: x2.5 (Area Ratio x6.25) with 105mm F2.8 Macro Lens Working Distance: 60mm - 85mm (from the front lens surface)  Weight (air): 410g Weight (water): 280g Diameter: 71.7 mm Length: 42.4mm Depth rating: 60m