Tronixpro 72mm Pro Series Hard Tulip Lens Hood For Sigma 18-35mm f/1.8 DC HSM Lens, Sigma 18-35mm f/1.8 DC HSM Lens, Sigma 17-70mm f/2.8-4 DC Macro OS HSM Lens This lens hood prevents image-degrading lens flare by blocking stray light from striking the surface of the lens It protects lenses from expensive front element damage Protects the front barrel from the inevitable impacts against walls, door frames, and other real-life obstacles. Microfiber Cloth 72mm Tulip Lens Hood