This lens hood snaps onto the AF-S DX NIKKOR 18-55mm f/3.5-5.6G VR lens (comes w/ Nikon D3100) and the AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6G ED II lens. Squeeze into an oval shape and pull to remove. By reducing the amount of non-essential light falling onto the front lens element, lenses can better achieve their optimum optical performance, producing more saturated images. In less-than-ideal lighting conditions, the performance difference can be substantial. Lens hoods also protect your lens from accidental damage. I'd love to hear if you use this. Thanks and enjoy!Simply print in PLA or ABS at 30% infill and 1 shell. I recommend using black material, but other colors may work too.