Sky-Watcher Explorer-150PDS (EQ3-2) 150mm (6"") f/750 Parabolic Dual-Speed Newtonian Reflector. The new Sky-Watcher EXPLORER-150PDS range of Newtonian Reflector incorporates the same superb mirror-set as the Explorer-150P Black Diamond Series, but with two significant advantages. A Dual-Speed 10:1 ratio focuser is now included for excellent focusing precision. Also the tube length has been slightly shortened to optimise performance for prime-focus photography.Even better performance for astro-photography and visual use can be achieved when used in combination with Sky-Watcher's Newtonian coma corrector. (Product Code 20233).