Amazon.com : Gosky Metal 1.25'' Telescope Camera T-Adapter and Nikon T2 T-Ring Adapter for Nikon DSLR SLR (Fits Nikon D90, D80, D70, D60, D50, D40x, D40, D800, D700 and All Nikon SLR
Full Metal Telescope Camera Adapter T Ring + 1.25" Telescope Mount Adapter + Extension Tube for Nikon DSLR / Canon EOS DSLR|Monocular/Binoculars| - AliExpress
All in one: LM Digital SLR Universal Adapter for phototube and the eyepiece tube (C-Mount, 23.2mm, 30mm 37mm, 38mm, 42mm)