It is 100% fine mate as long as it ain't the auto version. I've imported them numerous times before and even in the dark days of the Aussie 'flick test' prohibition (thankfully now a thing of the past) two hand openers were fine to import.
General rules are now:
A) manual folders including flippers all good;
B) No daggers, balisongs, autos, k bits, assisted, concealed knives (i.e. Belt buckle blades), trench knives (any knives with a finger hole), gravity knives, push blades, throwing knives and any other dodgy stuff I missed which they deem to be for killin only. There is also something they don't like about non metal blades
In short your regular old pocket knife is all good mate!