This is a brand new Canon and Nikon SLR/DSLR Camera adapter for microscopes. With two microscope adapters included, it offers three different mounting sizes on microscope side, 23.2mm, 30mm and 30.5mm, fitting almost all kinds of microscopes including compound and stereo microscopes. Its retail value is $500. Features & Specifications: Compatible with Canon SLR/DSLR cameras including 30D, 40D, 50D, 300D, 350D, 400D, 450D, 500D, EOS Rebel XTi, EOS Rebel XS, EOS Rebel XSi, EOS Rebel T1i, T2i ... Compatible with Nikon SLR/DSLR cameras including D40, D40X, D50, D60, D70, D80, D90, D200, D300, D700, D5000, D7000 ... Magnification Power: 2X Material: metal Mounting Size on Microscope Side: 23.2mm, 30mm and 30.5mm Microscope Adapters Included: two adapters converting 23.2mm to 30mm and 30.5mm Camera Adapters Included: two ring adapters one for Canon cameras and another for Nikon cameras T-mount Connection Standard 23.2mm Work on Monocular (Eye Tube).