Last year while closing I noticed air coming around the plugged returns then found they could be just pulled out fully. I hadn't had to do that in previous years. I was curious did some glue just finally wear out? What are these called? 

They basically just were pushed into the returns and came out without too much trouble. The eye threading can unthread from them too.
Thanks!
Daum


They basically just were pushed into the returns and came out without too much trouble. The eye threading can unthread from them too.
Thanks!
Daum