Martin 1.6x T-MOUNT Universal adapter fits standard 23mm or 30mm eyetubes / phototubes, plus 1x C-mounts (sold separately). The 1.6x magnification factor provides a wide field of view for use with popular crop-sensor (APS-C) DSLR cameras. Includes your choice of T2 adapter for either Canon EOS or Nikon. Other T2 adapter (for Sony, etc) also available - contact us for info on these.