Olympus Stylus Tough TG-4 0.21x High Grade Fish-Eye Lens (180&deg; Diagonal Angle of View) + Lens Adapter (40.5mm) + Stepping Ring (40.5-37mm) 0.21x (Fisheye) High Definition Digital Lens Multi-Coated Optical Glass Metal Casing Optical Infrared Glass Ultra Compact. Dimensions: 0.9" (2.3cm), Weight 0.5 lbs (0.226 kg)