ZWO 131mm Quad APO Refractor Dew Control The 70mm objective lenses offer

The 70mm objective lenses offer plenty of light-gathering ability for superior low-light performance

The blue and green filter passbands overlap slightly to include emission from OIII to help achieve a more natural color when imaging nebulae

This is a an Open Box return of a ZWO OAG-L

the Autoguider boosts tracking precision for longer manual exposures—reducing rejected frames and maximizing image quality

With a large 8" Newtonian reflector optical tube

ZWO 131mm Quad APO Refractor Dew Control The 70mm objective lenses offerZWO FF131 APO Flat Field Apochromatic Refractor *Focus can be achieved within a back focus range of 4273 mm, measured from the M54M48 interface shoulder. Main Features Flexible Connectivity for Multiple Configurations Uniqueness Four Element Optical Design The FF131 APO features a four element, fully air spaced apochromatic optical design. All four elements work together to deliver a flat imaging field without the need for an additional field