Consists of three parts for both prime focus and eyepiece projection photography with 1.25" focuser refractors and reflectors. Not recommended for Schmidt-Cassegrain or Maksutov-Cassegrain telescopes. The 1.25" chrome barrel prime focus section is used by itself (with an optional T-ring) for prime focus lunar and terrestrial photography. The prime focus section and eyepiece projection section are screwed together for eyepiece projection photography (using the same optional T-ring). The eyepiece projection section consists of two nested tubes. The outer tube (to which the camera attaches) can be shortened or lengthened to change the projection distance from 90mm to 125mm. The telescoping outer tube is held firmly at the desired projection distance by two thumbscrews. The variable projection distance design allows you to change the magnification to vary the size of the image by 44% without the need to change to a different focal length eyepiece. Eyepieces with rubber eyecups may not fit into the camera adapter without temporarily removing the eyecup. Needs optional T-ring. Threaded for 1.25" filters.