Synonyms for shock absorber

I was not with them when they discovered the first clewI think it was a shock absorber; was it not, Walter?

But Betty thought that she would not enjoy being a shock absorber and felt none too comfortable.

I need you as a shock absorber, said Lucia in a low tone, a half smile twisting her lips, and Betty made a low response.

The blind adult soon realizes that "humor is a shock absorber," and that "mirth is the soul's best medicine."