The ES-52 Lens Hood from Canon is designed to fit the Canon 40mm EF f/2.8mm STM, EF-S 24mm f/2.8 STM, and EF-M 18-55mm f/3.5-5.6 IS STM lenses. Lens hoods offer protection from unwanted light entering your lens and causing glare, especially when shooting toward your light source. They also offer a degree of physical protection for your lens against accidental bumps.