下句中“using a counterbalance system”是定语还是状语？

Owners push a button, and the rooms fold out like an accordion using a counterbalance system.

请问老师，绿色部分是前面an accordion的定语还是句子的状语？谢谢老师的回答。

Owners push a button, and the rooms fold out like an accordion using a counterbalance system.

业主们按下一个按钮，通过一种平衡系统，一个个房间就像手风琴一样打开了。

using a counterbalance system.这是目前分词短语作方法状语，修饰谓语fold out。不是定语。