求翻译：4、多功能水浴恒温振荡器具备回旋和往复两种功能，当需要选择不同的振荡方式时， 将开关拨向回旋或往复。是什么意思？

4, multi-functional and reciprocating water bath oscillator with roundabout two features, when you need to select a different mode of oscillation, will switch to the swing or reciprocating.