Power cord adapter.

电源适配器。

youdao

Most of the time I keep the longer cord attached to my power adapter, but sometimes I like (or need) to have it set up in the more compact form.

平时一般都将电源线插在电源适配器，但是有时候我需要多腾出来一点空间。

youdao

PlugBug uses the clever trick of attaching to any Apple MacBook Power Adapter by replacing its attached plug or extended power cord.

ENGADGET: PlugBug World brings global travel to the MacBook / USB charger