Can anyone tell me what this is?

[PeterM]

It was under a sink in a cabin that has to be winterized, so that the sink can be drained each fall. It's obviously some jury rigged stopper, which is all well and good, but I cannot identify what the brand/description for the blue connector. It's some sort of press on connector, since I cannot get the name brand, not sure if I am connecting properly....Thanks in advance.

 

[PlumbNuts]

On some kitchen faucets that have a sidesprayer they will give you the option of not using the sidesprayer; if that is the choice made then you would not attach the sidesprayer but instead you would attach the piece that you have pictured there.