The Meade 07049 f/6.3 Focal Reducer & Field Flattener is a 4-element multicoated 41mm lens in a metal cell which threads upon the 2.00"-18 rear cell thread of any 8.0-16.0" Meade Schmidt-Cassegrain or Ritchey-Chrétien telescope. It also is compatible with Meade's lineup of APO refractors and 7.0" Maksutov-Cassegrains(though not ideal for either, because they don't benefit from the field-flattening influence).
The Meade f/6.3 Focal Reducer & Field Flattener reduces the telescope's effective focal ratio by a factor of 0.63. Thus an f/10.0 Schmidt-Cassegrain becomes an f/6.3, an older f/6.3 becomes a f/4.0 and an f/8.0 Ritchey-Chrétien becomes an f/5.0 system. With these drastic changes upon the telescope aperture, your exposure times will significantly shorten, making astrophotography easier.
The lens of the f/6.3 Focal Reducer & Field Flattener also improves the edge-of-field resolution of the telescope by flattening its field.
2.00"-18 Female Threads On One End, 2.00"-18 Male Upon the Other
Duplicates telescope's rear cell thread, allowing attachment of standard rear cell accessories
Rubber grip ring allows easy installation when wearing gloves
Ideal for reduction of magnification with terrestrial viewing or for shortening exposure times in astrophotography