PARKS 6" f/8 Parabolic Primary Mirror, focal length 48"/1220mm; 1" thick; 2.2 lb.
Parks Parabolic Primary Mirrors are made of premium fine annealed, low expansion Pyrex, with a full 1:6 ratio of thickness to diameter. Individually hand-figured by a skilled optician, each disk produces a good diffraction ring with no turned edges or edge zones. The optical surface exhibits straight Ronchi bands edge to edge under the sensitive double pass auto-collimation test. Aluminized and silicon monoxide over coated for long lasting performance.