The pentax da 55 300mm f45 63 plm wr is a compact weather resistant telephoto lens designed for use with pentax kaf4 mount dslrs such as the k 70 k 1 k 3 ii k s2 and k s1 it provides focal lengths of between 845 460mm when used on an aps c sensor camera and has an upgraded af system that assures quiet high speed af operation particularly when used with the new pentax k 70 at just 89mm in length and an approximate weight of 442g it is entirely weather sealed making it a convenient