Olympus M.ZUIKO DIGITAL ED 12-40mm F2.8 PRO Interchangeable Lens Constant f2.8 maximum aperture Focal length : 12-40mm, Minimum Focus Distance-7.87 inches (20 cm) Drip Proof;Dustproof, Splash proof, and Freeze proof construction. Lens Construction:14 Elements in 9 Groups (Aspherical ED lens, 2 Aspherical lenses, DSA lens, 2 ED lenses, HD lens, 2 HR lense) Includes lens hood and pouch,Filter Size 62mm, Equipped with manual focus clutch mechanism Compatible with Olympus and Panasonic cameras Constant f2.8 maximum aperture Focal length : 12-40mm, Minimum Focus Distance-7.87 inches (20 cm) Dustproof, Splash proof, and Freeze proof construction Includes lens hood and pouch,Filter Size 62mm, Equipped with manual focus clutch mechanism Compatible with Olympus and Panasonic cameras