Sump discharge-unknown device

Anyone seen these installed on a sump pump discharge? There is a radon mitigation system installed and the sump pit has been sealed. This is located above the check valve. It appears that the plastic lock can be removed, which I did not remove. I am unable to determine what it is, although i am thinking it is some type of valve. No markings except the tag.

It’s a gate valve so you can close the line to service the check valve.

Duh!! It seems so obvious now. Thanks