Comfortable viewing even at high magnifications. Phantom Group coating in Zeiss class for complete freedom from reflections and maximum image contrast. 1¼" and 2" insert diameters allow for variable focal lengths. Multiple threads for camera and accessory connections, as well as afocal and normal eyepiece projection, are possible. The eyepiece can be unscrewed for use with 2" filters, allowing these filters to be used as well.