ZWO 65mm Quad APO RefractorThe smallest refractor in ZWO's line, the FF65 APO is differentiated from its larger relatives by featuring a 5 element, 3+2 air spaced quintuplet lens design! Two lenses are made of extra low dispersion (ED) glass to minimize chromatic and other aberrations. Its self flattening design provides a flat field for imaging without the need of an additional field flattener accessory. Multiple included adapters give versatility to connecting a variety of