The Sky-Watcher BK130PDS OTAW Dual Speed incorporates superb mirror-set 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 optimize performance for prime-focus photography. Even better performance for astrophotography and visual use can be achieved when used in combination with Sky-Watcher’s Newtonian coma corrector.