Sky watcher explorer 130pds 130mm 5 f650 parabolic dual speed newtonian reflector optical tube assembly the new sky watcher explorer 130pds range of newtonian reflectors incorporate the same superb mirror set as the explorer 130p black diamond series but with two significant advantages a dual speed 101 ratio focuser is now included for excellent focusing precision also the tube length has been slightly shortened to optimise performance for prime focus photographyeven better performanc