Compatible with Nikon SLR / DSLR Models. including: D1, D2, D3, D3S, D3X, D35, D4, D40, D40X, D50, D60, D70, D80, D90, D100, D200, D300, D300S, D600, D700, D750, D800, D800E, D810, D3000, D3100, D3200, D5000, D5100, D5200, D7000, D7100, etc. Note: it doesn't fit mirrorless cameras. Three ways to use it'. 1. A 2x barlow; 2. a universal 1.25-inch Camera T-Adapter; 3. 1.25-Inch Telescope Eyepiece Extension Tube. Works on most brands of telescope. The barlow is made from quality coated optics and metal Framework. Precisely CNC-machined. Celticbird 1.25 Inch Camera T-Adapter with 2x Barlow Lens and SLR Camera Adapter Kit