It's a three pronged plug, and this is an earth prong.

这是一个三叉插头，这是一个土拨管。

Its three pronged hands can be controlled remotely by a person in another location.

它的三叉手可以由人在另一个地方远程控制。

We have a three pronged plug which is different to the European plugs, so make sure you bring an adaptor with you.

我们有一种与欧洲插头不同的三管插头，所以大家过来的话一定要带一个适配器。