For Dslr Af, N-af1-b, Meike Macro Lens For Camera, Adapter Ring For Nikon D3100 D5000, 12, 20, 36mm, With Auto Focus, All Lenses - Lens Adapter - AliExpress
Nikon D3100 Review
Amazon.com : 58MM 0.45 x Wide Angle Macro Lens for Nikon D3200 D3100 D5200 D5100 : Electronics
52MM EXTREME SPORT FISHEYE LENS + MACRO FOR NIKON D3100 D3200 D3300 D5000 D5100 | eBay