Specifications: Model: A14NK300S Material: metal Compatible with Nikon D-SLR cameras Nikon/Olympus CMOS/CCD sensor with 2X lens 23.2mm-30.0mm metal ocular tube adapter Tube depth: 25.0mm Packing List: 2X lens for microscopes, 42mm male thread Nikon DSLR adapter ring, 42mm female thread 1 piece of 23.2--30.0mm metal ocular tube adapter