Martin 1.6x T-MOUNT adapter for all 23mm I.D. / 25mm O.D. photoports. 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.